ライフサイエンスコーパス: MoFe protein

1 ey player in the biosynthesis of nitrogenase MoFe protein.

2 t is delivered to the target location in the MoFe protein.

3 rs that are homologous to those found in the MoFe protein.

4 nalogous clusters observed in the Delta nifH MoFe protein.

5 iated with the maturation of the nitrogenase MoFe protein.

6 Fe protein, and (4) the stepwise assembly of MoFe protein.

7 of the P-cluster and the conformation of the MoFe protein.

8 in the wild-type and DeltanifB forms of the MoFe protein.

9 for the nitrogenase alpha-195Gln-substituted MoFe protein.

10 ally compromised in alpha-195Gln-substituted MoFe protein.

11 Fe-S] cluster is identified in the DeltanifH MoFe protein.

12 substrate for the wild-type (alpha-70(Val)) MoFe protein.

13 ed by Fe L(2,3) -edge XMCD within the intact MoFe protein.

14 CO" state) to FeMo-cofactor in the wild-type MoFe protein.

15 ing components called the Fe protein and the MoFe protein.

16 s from the FeMo cofactor center in wild-type MoFe protein.

17 +) state of the P-cluster of the Delta(nifB) MoFe protein.

18 tion of both P-clusters contained within the MoFe protein.

19 t assigned to FeMo-cofactor in the wild-type MoFe protein.

20 ined a fully active reconstituted E146D nifH MoFe protein.

21 signals are not recognized for the wild-type MoFe protein.

22 oco into the partially pure FeMoco-deficient MoFe protein.

23 o) cofactor contained within the nitrogenase MoFe protein.

24 lex is formed at a lower ratio of Fe protein/MoFe protein.

25 ) are likely reduced at the same site on the MoFe protein.

26 he oxidized, MgADP-bound Fe protein from the MoFe protein.

27 ation of oxidized Fe protein-(ADP)2 from the MoFe protein.

28 with each alphabeta half of the alpha2beta2 MoFe protein.

29 f photoexcited electron delivery from CdS to MoFe protein.

30 een the Fe(ox)(ADP)2 protein and the reduced MoFe protein.

31 duction at rates up to 170 nmol NH(3)/min/mg MoFe protein.

32 )-reducing ability of the cofactor-deficient MoFe protein.

33 e component proteins, the Fe protein and the MoFe protein.

34 vers one electron at a time to the catalytic MoFe protein.

35 teractions of C(2)H(2) and C(2)H(4) with the MoFe proteins.

36 of P-clusters in DeltanifH molybdenum-iron (MoFe) protein.

37 erent from the P-cluster of molybdenum iron (MoFe) protein.

38 NifEN, (2) the incorporation of FeMoco into MoFe protein, (3) the in situ assembly of P-cluster on M

39 he metal cluster structures in the DeltanifH MoFe protein, a variable-temperature, variable-field mag

40 FeMo-cofactor in the Azotobacter vinelandii MoFe-protein, a position that was recently identified as

41 rotein complexes led to redox changes in the MoFe protein active site FeMo-co observed as the gradual

42 With the alpha-195(Asn) MoFe protein, added C(2)H(2) decreased the rates of both

43 With the alpha-195(Gln) MoFe protein, added C(2)H(2) decreased the rates of both

44 -type MoFe protein, the alpha-96-substituted MoFe proteins all exhibit changes in their EPR spectra u

45 ocatalysis to drive electron delivery to the MoFe protein allowing examination of the mechanism of H2

46 ion to FeMo cofactor requires His-195 of the MoFe protein alpha subunit.

47 Substitution of the MoFe protein alpha-70(Val) residue with Ala or Gly expan

48 Here, we report that when the nitrogenase MoFe protein alpha-Val(70) residue is substituted by ala

49 lanine, and the resulting doubly substituted MoFe protein (alpha-70(Ala)/alpha-195(Gln)) is turned ov

50 A doubly substituted form of the nitrogenase MoFe protein (alpha-70(Val)(-->Ala), alpha-195(His-->Gln

51 Incubation of cyanide with the alpha-96(Leu) MoFe protein also decreased the FeMo-cofactor EPR signal

52 The alpha-Gln(195) MoFe protein also exhibits these signals when incubated

53 The doubly substituted MoFe protein also has the capacity to catalyze the unpre

54 face of the FeMo-cofactor approached by the MoFe protein amino acid alpha-70(Val).

55 ver were investigated for the alpha-Gln(195) MoFe protein, an altered form for which the alpha-His(19

56 to be larger than the wild-type or DeltanifB MoFe proteins, an increase in size that can be modeled w

57 tetramer that is structurally similar to the MoFe protein and encoded as two separate polypeptides by

58 ajor revision of the rate-limiting step from MoFe protein and Fe protein dissociation to release of P

59 the reduced, MgATP-bound Fe protein and the MoFe protein and includes electron transfer, ATP hydroly

60 owever, N(2) was bound by the alpha-195(Asn) MoFe protein and inhibited the reduction of both protons

61 e that they arise from reduced states of the MoFe protein and reflect different conformations of the

62 the normal P cluster found in the DeltanifB MoFe protein and suggest the presence of [4Fe-4S]-like c

63 dy has been undertaken on both the DeltanifB MoFe protein and the DeltanifH MoFe protein in both the

64 The structural similarity between the MoFe protein and the NifEN complex prompted us to test w

65 wo halves of the ternary complex between the MoFe protein and two reduced Fe protein-(ATP)2 do not un

66 e of the nitrogenase with the alpha-191(Lys) MoFe protein and was a poor substrate of the nitrogenase

67 anifH MoFe protein is less stable than other MoFe proteins and has been shown by extended X-ray absor

68 he interactions at the interface between the MoFe-protein and Fe-proteins are conserved in the two co

69 from the Fe-protein to the catalytic site of MoFe-protein and how energy from ATP hydrolysis transduc

70 in, (3) the in situ assembly of P-cluster on MoFe protein, and (4) the stepwise assembly of MoFe prot

71 ns, designated the iron (Fe) protein and the MoFe protein, and minimally requires 16 magnesium ATP (M

72 odels for the [Fe-S] center in the DeltanifH MoFe protein are constructed, the most likely of which c

73 [Fe(4)S(4)]-like cluster pairs in DeltanifH MoFe protein are indeed the precursors to P-clusters, wh

74 itrogen and acetylene binding to the altered MoFe protein are mutually competitive.

75 pped intermediate of the alpha-70(Val-->Ile) MoFe protein as the Janus intermediate that stores four

76 ever, it is only a "skeleton" version of the MoFe protein, as its associated clusters are simpler in

77 he cofactor is inserted in the final step of MoFe protein assembly.

78 studies have identified factors involved in MoFe protein assembly; however, the exact functions of t

79 s a conformation very similar to that of the MoFe protein-associated FeMoco.

80 netics of oxidation of the Fe protein by the MoFe protein at a constant pH of 7.4 fixed by the buffer

81 no acid residues in the alpha-subunit of the MoFe protein at positions alpha-191 and alpha-195 in sub

82 (CO)-inhibited nitrogenase molybdenum-iron (MoFe)-protein at 1.50 angstrom resolution, which reveals

83 ort that when a single amino acid within the MoFe protein (beta-98(Tyr)) is substituted by His, the r

84 The CdS:MoFe protein biohybrids provide a photochemical model fo

85 ein could represent an early intermediate in MoFe protein biosynthesis where the P-cluster precursors

86 However, for the alphaSer(69) MoFe protein both CO and acetylene have become competiti

87 g either the wild-type or the alpha-195(Gln) MoFe protein, both of which had a low V(max) and high K(

88 derable degree of sequence homology with the MoFe protein, but also contains clusters that are homolo

89 next to the active site FeMo-cofactor in the MoFe protein by leucine, glutamine, alanine, or histidin

90 conditions that prevent electron delivery to MoFe protein, can be analyzed to reveal n and the nature

91 15N ENDOR spectroscopic analysis of MoFe protein captured during turnover with 15N2 revealed

92 tructure of the nitrogenase molybdenum-iron (MoFe) protein captured under physiological N(2) turnover

93 r these conditions, whereas the beta-98(His) MoFe protein catalyzes hydrazine reduction at rates up t

94 imized conditions, 1 nmol of the substituted MoFe protein catalyzes the formation of 21 nmol of CH(4)

95 Increased electron flux through the MoFe protein caused these signals to form more rapidly.

96 properties of FeS clusters in the DeltanifH MoFe protein clearly differ from those of the normal P c

97 ster in the oxidized DeltanifB beta-188(Cys) MoFe protein closely resembles that of the P(2+) state i

98 ypeptides and then assembled into tetrameric MoFe protein complex that includes two types of metal ce

99 ed to prolong the lifetime of the Fe-protein-MoFe-protein complex and, in turn, could orchestrate the

100 Illumination of CdS QD:MoFe protein complexes led to redox changes in the MoFe

101 The MoFe protein component carries an [8Fe-7S] group called

102 The MoFe protein component of the complex metalloenzyme nitr

103 FeMo-cofactor located within the nitrogenase MoFe protein component provides the site of substrate re

104 ccur upon initial complex formation with the MoFe protein component that are distinct from the protei

105 a at the cofactor (i.e., FeMoco) site of its MoFe protein component.

106 (ET) from the nitrogenase Fe protein to the MoFe protein concluded that the mechanism for ET changed

107 on-molybdenum cofactor-deficient nitrogenase MoFe proteins contain the P-cluster, although no biosynt

108 and Fe L(2,3) -edge XMCD spectroscopy of the MoFe protein (containing both FeMoco and the 8Fe-7S P-cl

109 The Delta(nifH) MoFe protein contains 18.6 mol Fe/mol and, upon reductio

110 ach half of the dithionite-reduced DeltanifH MoFe protein contains a [4Fe-4S]+ cluster paired with a

111 ne alpha beta subunit pair of the Delta nifZ MoFe protein contains a P cluster ([8Fe-7S]) and an iron

112 These results suggest that the DeltanifH MoFe protein contains a pair of neighboring, unusual [4F

113 The nitrogenase MoFe protein contains the active site metallocluster cal

114 ron transfer, whereas the active site of the MoFe protein contains the polynuclear FeMo cofactor, a s

115 lted in the formation of 286 nmol NH3 mg(-1) MoFe protein, corresponding to a Faradaic efficiency of

116 The active site of the nitrogenase MoFe protein corresponds to a [MoFe(7)S(9)C-(R)-homocitr

117 ifEN complex prompted us to test whether the MoFe protein could also be functional when synthesized a

118 Thus, DeltanifH MoFe protein could represent an early intermediate in Mo

119 cubation of acetylene with the alpha-96(Leu) MoFe protein decreased the intensity of the normal FeMo-

120 ts in the formation of a variant nitrogenase MoFe protein (DeltanifB MoFe protein) that appears to co

121 been applied to Se-substituted CO-inhibited MoFe protein, demonstrating the ability of these methods

122 n of substrate reduction, the alpha-195(Asn) MoFe protein did not catalyze HD formation under a N(2)/

123 The indigo disulfonate-oxidized Delta(nifH) MoFe protein does not show features of the P(2+) state o

124 e-protein) and its target catalytic protein (MoFe-protein), driving the reduction of dinitrogen into

125 ATP molecules, transfers one electron to the MoFe protein during each association, coupled to the hyd

126 photoexcited CdS delivers electrons into the MoFe protein during reduction of N(2) to ammonia and the

127 around the active site FeMo-cofactor in the MoFe protein, either by substituting nearby amino acids

128 also varied with the ratio of Fe protein to MoFe protein (electron flux through nitrogenase), with t

129 he Fe protein transferring two electrons per MoFe protein encounter using the [Fe(4)S(4)](2+)/[Fe(4)S

130 ectra obtained from whole cells and purified MoFe protein established that the N coordination of the

131 ion that the rate constant for Fe protein to MoFe protein ET decreases strongly, with a nonlinear Arr

132 otein, association of an Fe protein with the MoFe protein, ET from the Fe protein to the MoFe protein

133 Altered MoFe proteins examined included those having the alpha-s

134 esentative of the other alpha-96-substituted MoFe proteins examined.

135 virtually identical to that of the wild-type MoFe protein except for replacement of an NuH-S hydrogen

136 n has the same composition as the Delta nifZ MoFe protein except for the absence of FeMoco, an effect

137 of the P(2+) state in the oxidized wild-type MoFe protein, except for the absence of a major charge-t

138 The His-tag MoFe protein expressed by the nifH deletion strain Azoto

139 The 1:1 complex, MoFe protein-Fe protein x (ADP x AlF(4)(-))(2), formed w

140 The MoFe protein folds as a heterotetramer containing two co

141 ty of synchronizing electron delivery to the MoFe protein for generation of specific enzymatic interm

142 e varying apparent affinities of the altered MoFe proteins for HCN and CN(-), is advanced to explain

143 troscopy of the nitrogenase molybdenum iron (MoFe) proteins from two phylogenetically distinct nitrog

144 Molybdenum-iron protein (MoFe protein) from the strain expressing the E146D Fe pr

145 GHz ENDOR measurements of a (95)Mo enriched MoFe protein, further comparing the results with those f

146 was undertaken on the Delta nifB Delta nifZ MoFe protein generated in the absence of both NifZ and N

147 S-Mo-homocitrate-X]; FeMo-co) only after the MoFe protein has accumulated three or four electrons/pro

148 Likewise, the Delta nifZ Delta nifB MoFe protein has the same composition as the Delta nifZ

149 As the P-clusters of MoFe protein have an S=0 total spin, these are effective

150 Also, NifW could associate with MoFe protein having immature P-clusters and became disso

151 FeMo-cofactor and mature P-cluster, inactive MoFe protein having no FeMo-cofactor and only immature P

152 nly immature P-cluster, and partially active MoFe protein having one alphabeta-unit with a FeMo-cofac

153 )D(2) reduction stereospecificity of altered MoFe proteins having amino acid substitutions within the

154 The iron-sulfur scattering of the DeltanifH MoFe protein, however, indicates differences in its clus

155 suggest that NifEN is a catalytic homolog of MoFe protein; however, it is only a "skeleton" version o

156 MoFe protein, ET from the Fe protein to the MoFe protein, hydrolysis of the two ATP to two ADP and t

157 and that P-cluster is assembled stepwise on MoFe protein, i.e., one cluster is assembled before the

158 P-clusters in the alpha(2)beta(2)-tetrameric MoFe protein, i.e., one P-cluster is formed in one alpha

159 h subsequent transfer of one electron to the MoFe protein in a reaction coupled to the hydrolysis of

160 the DeltanifB MoFe protein and the DeltanifH MoFe protein in both the dithionite-reduced and oxidized

161 The resemblance of NifEN to MoFe protein in catalysis points to a plausible, sequent

162 s of the two metal clusters contained in the MoFe protein in catalysis, insights gained from recent s

163 N(2)H(4)) to ammonia by a beta-98(Tyr-->His) MoFe protein in the absence of the Fe protein or ATP is

164 of the intracomplex oxidation of Fe(red) by MoFe protein in the presence of a variety of solutes.

165 substrates or inhibitors are incubated with MoFe protein in the resting state.

166 or contained within the alpha-96-substituted MoFe proteins in the resting state.

167 omplex with the nitrogenase molybdenum iron (MoFe) protein in the absence of nucleotide.

168 ase, Fe-protein, to the catalytic component, MoFe-protein, in an ATP-dependent fashion.

169 Finally, the alpha-96(Leu)-substituted MoFe protein incubated with (13)C-labeled cyanide displa

170 m cofactor-deficient form of the nitrogenase MoFe protein, into which the cofactor is inserted in the

171 er (ET) from the Fe protein to the catalytic MoFe protein involves a series of synchronized events re

172 The nitrogenase MoFe protein is a heterotetramer containing two unique h

173 The oxidized Delta(nifH) MoFe protein is able to form a specific complex with the

174 mical electron delivery from nanocrystals to MoFe protein is able to support the multielectron ammoni

175 The MoFe protein is an alpha(2)beta(2) heterotetramer that h

176 Assembly of nitrogenase MoFe protein is arguably one of the most complex process

177 of the FeMo cofactor (FeMoco) of nitrogenase MoFe protein is arguably one of the most complex process

178 ne alpha beta subunit pair of the tetrameric MoFe protein is assembled prior to the other, and that N

179 The alpha(2)beta(2) tetrameric Delta(nifH) MoFe protein is FeMoco-deficient based on metal analysis

180 These results imply that the MoFe protein is flexible in that it can accommodate majo

181 The DeltanifH MoFe protein is found to be larger than the wild-type or

182 When the alpha-70(Ile) MoFe protein is freeze-trapped during H(+) reduction und

183 The DeltanifH MoFe protein is less stable than other MoFe proteins and

184 These results suggest that the MoFe protein is likely assembled stepwise, i.e. one alph

185 NifZ, only one of the two P-clusters of the MoFe protein is matured to the ultimate [8Fe-7S] structu

186 n-iron scattering displayed by the DeltanifH MoFe protein is more similar to that of a standard [Fe(4

187 The DeltanifH MoFe protein is not reconstituted to the holo MoFe prote

188 s indicates that a more reduced state of the MoFe protein is required to accommodate substrate or inh

189 These results suggest that the MoFe protein is synthesized in a stepwise fashion where

190 moiety bound to FeMo-cofactor when the same MoFe protein is trapped during turnover with hydrazine.

191 MoFe proteins isolated from different genetic background

192 ion spectroscopy (XES) of intact nitrogenase MoFe protein, isolated FeMoco, and the FeMoco-deficient

193 ), and (iv) Fe protein dissociation from the MoFe protein (kdiss = 6 s(-1), 25 degrees C).

194 filtration chromatography data show that the MoFe protein lacking a full complement of the cofactor f

195 and NifB (deletion of NifB generates an apo-MoFe protein lacking the FeMo cofactor).

196 f how NifZ carries out its exact function in MoFe protein maturation awaits further investigation.

197 zotobacter vinelandii has been implicated in MoFe protein maturation.

198 process, the nitrogenase component proteins, MoFe-protein (MoFeP) and Fe-protein (FeP), repeatedly as

199 e crystal structures of reduced and oxidized MoFe-protein (MoFeP) from Gluconacetobacter diazotrophic

200 homologous to the catalytic molybdenum-iron (MoFe) protein (NifDK) component of nitrogenase.

201 action intermediates of CdS quantum dot (QD):MoFe protein nitrogenase complexes under photochemical a

202 sistent with other studies that indicate the MoFe protein normally contains at least two acetylene bi

203 photophysical measurements on wild type (WT) MoFe protein now establish this mechanism.

204 binding site(s) on the FeMo cofactor of the MoFe protein of Azotobacter vinelandii nitrogenase were

205 otron x-ray solution scattering data for the MoFe protein of Klebsiella pneumoniae nitrogenase and sh

206 Altered MoFe proteins of Azotobacter vinelandii Mo-nitrogenase,

207 n of a complex between the component Fe- and MoFe-proteins of nitrogenase represents a central event

208 he P(+) state in the DeltanifB beta-188(Cys) MoFe protein, on the other hand, is associated with a cl

209 antly, it is catalytically distinct from the MoFe protein, particularly with regard to the mechanism

210 ently shown that the alpha-70 residue of the MoFe protein plays a significant role in defining substr

211 ination of the FeMo cofactor provided by the MoFe-protein polypeptide matrix can be unambiguously rec

212 s the P-cluster is assembled directly on the MoFe protein polypeptides.

213 kinetic features of the altered nitrogenase MoFe protein produced by this strain, which has serine s

214 aturation pattern of P-clusters in DeltanifH MoFe protein provides dynamic proof for the previously h

215 ural nitrogenase substrate, N2, by wild-type MoFe protein, providing evidence that it contains N2 bou

216 l/biophysical characterization of His-tagged MoFe proteins purified from A. vinelandii nifZ and nifZ/

217 anscripts, supporting the high Fe protein-to-MoFe protein ratio required for optimal diazotrophic gro

218 The beta-98(His) MoFe protein reduction of hydrazine in the absence of th

219 acter vinelandii These included fully active MoFe protein replete with FeMo-cofactor and mature P-clu

220 Here we investigate the role of a MoFe protein residue (Trp-alpha444) in the final step of

221 d YM6A (Delta nifZ and Delta nifZ Delta nifB MoFe proteins, respectively).

222 lu 112 and Lys beta400 of the Fe-protein and MoFe-protein, respectively.

223 All of the MoFe proteins responded differently to the addition of C

224 ine structure analyses of cofactor-deficient MoFe proteins resulting from nifH and nifB deletion stra

225 und to form a high affinity complex with the MoFe protein, revealing that alteration on one subunit i

226 tion, the VTVH-MCD spectrum of the DeltanifH MoFe protein reveals a paramagnetic, albeit EPR-silent s

227 crystallographic analysis of the nitrogenase MoFe-protein reveals a previously unrecognized ligand co

228 The MoFe protein's catalytic partner, Fe protein, is also re

229 alous diffraction studies on the nitrogenase MoFe protein show the presence of a mononuclear iron sit

230 alpha-96(Ala)-, or alpha-96(His)-substituted MoFe proteins show an S = 3/2 EPR signal (g = 4.26, 3.67

231 tein cannot interact with flavodoxin and the MoFe protein simultaneously, knowledge of the interactio

232 Moreover, after a MoFe-protein solution had been pretreated (using conditi

233 and MALDI measurements, we show that several MoFe protein species accumulate in a NifZ-deficient back

234 the already small value in the resting state MoFe protein strongly suggests that the resting Mo(IV) i

235 tein subunits connected to the two different MoFe-protein subunits.

236 ves of DeltanifB beta-188(Cys) and wild-type MoFe proteins suggest that the P(2+) species in both pro

237 FeMoco insertion into pure FeMoco-deficient MoFe protein, suggesting that there are still other prot

238 ention and drastically reduced activities of MoFe proteins, suggesting that Trp-alpha444 may lock the

239 8(Tyr)) is substituted by His, the resulting MoFe protein supports catalytic reduction of the nitroge

240 mutually exclusive interaction sites on the MoFe-protein surface that are selectively populated, dep

241 Because the MoFe protein tetramer has two separate alphabeta active

242 of P-cluster precursors into a region of the MoFe protein that is buried in the wild-type conformatio

243 protein x (ADP x AlF(4)(-))(2), formed with MoFe protein that lacks one of the cofactors, is stable.

244 alanine, or histidine is found to result in MoFe proteins that can interact with acetylene or cyanid

245 variant (designated DeltanifB beta-188(Cys) MoFe protein) that accumulates the P(+) form of P-cluste

246 nifH results in a variant protein (DeltanifH MoFe protein) that appears to contain FeS clusters diffe

247 variant nitrogenase MoFe protein (DeltanifB MoFe protein) that appears to contain two normal [8Fe-7S

248 We suggest that, for the wild-type MoFe protein, the alpha-96(Arg) side chain acts as a gat

249 However, in contrast to the wild-type MoFe protein, the alpha-96-substituted MoFe proteins all

250 active-site metal cluster in the nitrogenase MoFe protein, the FeMo-cofactor ([7Fe-9S-Mo-homocitrate-

251 With the alpha-195(Asn) MoFe protein, the N(2)-induced inhibition of substrate r

252 With the alpha-191(Lys) MoFe protein, the rates of both CH(4) and NH(3) producti

253 With the alpha-195(Gln) MoFe protein, the rates of production of both CH(4) and

254 e iron (Fe) protein and the molybdenum-iron (MoFe) protein; the Fe protein mediates the coupling of A

255 a mature FeMoco upon transfer from NifEN to MoFe protein through direct protein-protein interaction.

256 and prevents association between the Fe and MoFe proteins, thus inhibiting electron transfer.

257 Coupling the nitrogenase MoFe protein to light-harvesting semiconductor nanomater

258 e) significantly lowered the capacity of the MoFe protein to reduce dinitrogen, hydrazine, or acetyle

259 ble of activating a FeMoco-deficient form of MoFe protein to the same extent as the isolated FeMoco.

260 interactions requires the incubation of the MoFe protein together with its obligate electron donor,

261 bdenum cofactor (FeMo-co) of the nitrogenase MoFe protein undergoes six steps of hydrogenation (e(-)/

262 protein can be reactivated to form the holo MoFe protein upon addition of isolated FeMo cofactor.

263 The altered MoFe proteins used were the alpha-195(Asn) or alpha-195(

264 This strain expresses a MoFe protein variant (designated DeltanifB beta-188(Cys)

265 of E(4) trapped with the alpha-70(Val-->Ile) MoFe protein variant through use of advanced ENDOR metho

266 Freeze-quenching a MoFe protein variant with alpha-195His substituted by Gl

267 Use of a MoFe protein variant, beta-188(Cys), which poises the P

268 e nitrogenase alpha-70(Ile) molybdenum-iron (MoFe) protein variant accumulates a novel S = (1)/(2) st

269 tron transfer between the Fe protein and the MoFe protein via interconversions between its various ox

270 NO(2) (-) and N(2) to NH(3) catalyzed by the MoFe protein via the polymer-bound redox moieties distri

271 When MoFe protein was frozen at 77 K during steady-state turn

272 The alpha-70(Ala) variant MoFe protein was rapidly frozen during reduction of prop

273 The alpha-96(Leu)-substituted MoFe protein was representative of the other alpha-96-su

274 195(Asn), alpha-195(Gln), and alpha-191(Lys) MoFe proteins was 59%, 159%, and 6%, respectively, of th

275 n Azotobacter vinelandii DJ1165 (Delta(nifH) MoFe protein) was purified in large quantity.

276 nifD, which encodes a subunit of nitrogenase MoFe protein, was found to result in a slower inactivati

277 s observed for the alpha-96(Leu)-substituted MoFe protein were found to follow Curie law 1/T dependen

278 e catalyzed by the beta-98(His) or wild-type MoFe protein when combined with the Fe protein, ATP, and

279 tosensitize the nitrogenase molybdenum-iron (MoFe) protein, where light harvesting replaces ATP hydro

280 FeMoco is assembled outside the MoFe protein, whereas the P-cluster is assembled directl

281 e nucleotide-dependent electron donor to the MoFe protein which contains the sites for substrate bind

282 hich contains a [Fe(4)S(4)] cluster, and the MoFe protein, which contains two different classes of me

283 DeltanifH, DeltanifBDeltanifZ, and DeltanifB MoFe protein, which corresponds to a decrease of the amo

284 alpha-histidine-195, and the alpha-191(Lys) MoFe protein, which has lysine substituting for alpha-gl

285 ontaining protein than that of the DeltanifB MoFe protein, which is shown to contain a "normal" P-clu

286 her the alpha-195(Asn) or the alpha-191(Lys) MoFe proteins, which also exhibited the highest rate of

287 ed were the alpha-195(Asn) or alpha-195(Gln) MoFe proteins, which have either asparagine or glutamine

288 ctural rearrangements differ between the two MoFe proteins, which may reflect differences in potentia

289 ESEEM spectra of altered MoFe proteins, which were produced in certain mutant str

290 A similar behavior is found for the MoFe protein with both cofactors occupied, but the high

291 turnover of the alpha-70(Ala)/alpha-195(Gln) MoFe protein with diazene or hydrazine as substrate corr

292 oFe protein is not reconstituted to the holo MoFe protein with isolated FeMo cofactor.

293 racterization of the alpha-70(Val)(-->)(Ala) MoFe protein with propargyl alcohol trapped at the activ

294 he (13)C ENDOR spectrum of the alpha-70(Ala) MoFe protein with trapped (13)C-labeled propargyl alcoho

295 The wild-type and a number of other MoFe proteins with amino acid substitutions do not show

296 well as nitrogenous and alkyne substrates by MoFe proteins with amino acid substitutions.

297 er (ET) from the Fe protein to the catalytic MoFe protein, with each ET coupled to the hydrolysis of

298 binds two MgATP and forms a complex with the MoFe protein, with subsequent transfer of one electron t

299 e altered Azotobacter vinelandii nitrogenase MoFe proteins, with substitutions either at alpha-195(Hi

300 nized and assigned to turnover states of the MoFe protein without C(2)H(4) bound.