ライフサイエンスコーパス: MoFe protein

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

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

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

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

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

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

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

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

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

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

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

12 with each alphabeta half of the alpha2beta2 MoFe protein.

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

14 ined a fully active reconstituted E146D nifH MoFe protein.

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

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

17 o) cofactor contained within the nitrogenase MoFe protein.

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

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

20 he nitrogenase containing the alpha-191(Lys) MoFe protein.

21 an electron-flux inhibitor with the 195(Asn) MoFe protein.

22 e FeMo cofactor-binding alpha-subunit of the MoFe protein.

23 C(2)H(2) hardly affected the alpha-191(Lys) MoFe protein.

24 P-dependent primary electron transfer to the MoFe protein.

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

26 ith long-range conformational changes in the MoFe protein.

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

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

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

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

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

32 ey player in the biosynthesis of nitrogenase MoFe protein.

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

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

35 nalogous clusters observed in the Delta nifH MoFe protein.

36 iated with the maturation of the nitrogenase MoFe protein.

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

38 e iron (Fe) protein and the molybdenum-iron (MoFe) protein.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

56 The two altered MoFe proteins also responded quite differently to azide.

57 eme, the two Fe protein binding sites of the MoFe protein alternately bind and release Fe protein in

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

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

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

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

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

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

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

65 ormation for productive interaction with the MoFe protein and on its ability to change redox potentia

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

95 15N ENDOR spectroscopic analysis of MoFe protein captured during turnover with 15N2 revealed

96 er the alpha-195(Asn) nor the alpha-191(Lys) MoFe protein catalyzed N(2) reduction to NH(3), when com

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

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

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

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

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

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

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

104 The MoFe protein component of the complex metalloenzyme nitr

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

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

107 rolling the affinity of association with the MoFe protein component.

108 led to the transfer of one electron into the MoFe protein component.

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

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

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

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

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

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

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

116 The nitrogenase MoFe protein contains the active site metallocluster cal

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

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

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

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

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

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

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

124 The alpha-191(Lys) MoFe protein did not interact with N(2).

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

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

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

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

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

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

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

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

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

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

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

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

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

138 CH(4) and NH(3) production from HCN with all MoFe proteins except for the alpha-191(Lys) MoFe protein

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

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

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

142 The MoFe protein folds as a heterotetramer containing two co

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

144 meters for an altered Azotobacter vinelandii MoFe protein for which the alphaGly(69) residue was subs

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

168 ectrons ([Fe(4)S(4)](2+)/[Fe(4)S(4)](0)) per MoFe protein interaction using Ti(III) but transferring

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

188 MoFe proteins isolated from different genetic background

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

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

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

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

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

194 zotobacter vinelandii has been implicated in MoFe protein maturation.

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

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

197 finding is consistent with the existence of MoFe protein molecules that contain only one FeMo cofact

198 In contrast to the wild-type MoFe protein, neither the alpha-195(Asn) nor the alpha-1

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

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

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

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

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

204 Altered MoFe proteins of Azotobacter vinelandii Mo-nitrogenase,

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

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

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

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

209 ized Fe protein and the one-electron-reduced MoFe protein plays an essential role.

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

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

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

213 he nitrogenase containing the alpha-195(Asn) MoFe protein produced cis-C(2)D(2)H(2) when turned over

214 (3)NH(2) quantification showed that all four MoFe proteins produced CH(3)NH(2).

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

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

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

218 ic activity was measured as a function of Fe:MoFe protein ratio for both a one- and a two-electron tr

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

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

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

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

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

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

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

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

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

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

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 MoFe protein specific activity was measured as a functio

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 ith the low resolution structure of purified MoFe protein that contains only one molybdenum per tetra

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

272 195(Asn), alpha-195(Gln), and alpha-191(Lys) MoFe proteins was 59%, 159%, and 6%, respectively, of th

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

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

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

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

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

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

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

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

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

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

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

284 MoFe proteins except for the alpha-191(Lys) MoFe protein, which still manifested its very low rate o

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

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

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

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

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

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

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

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

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

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

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

296 Incubation of Fe and MoFe proteins with each of the MgNTP molecules and AlF(4

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.