Academic Journal
The role of methionine 156 in cross-subunit nucleotide interactions in the iron protein of nitrogenase.
| Τίτλος: | The role of methionine 156 in cross-subunit nucleotide interactions in the iron protein of nitrogenase. |
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| Συγγραφείς: | Bursey EH; Department of Molecular Biology and Biochemistry, University of California, Irvine, California 92697-3900, USA., Burgess BK |
| Πηγή: | The Journal of biological chemistry [J Biol Chem] 1998 Nov 06; Vol. 273 (45), pp. 29678-85. |
| Τύπος έκδοσης: | Journal Article; Research Support, U.S. Gov't, P.H.S. |
| Γλώσσα: | English |
| Στοιχεία περιοδικού: | Publisher: Elsevier Inc. on behalf of American Society for Biochemistry and Molecular Biology Country of Publication: United States NLM ID: 2985121R Publication Model: Print Cited Medium: Print ISSN: 0021-9258 (Print) Linking ISSN: 00219258 NLM ISO Abbreviation: J Biol Chem Subsets: MEDLINE |
| Imprint Name(s): | Publication: 2021- : [New York, NY] : Elsevier Inc. on behalf of American Society for Biochemistry and Molecular Biology Original Publication: Baltimore, MD : American Society for Biochemistry and Molecular Biology |
| Ιατρικοί όροι (MeSH): | Oxidoreductases*, Adenosine Triphosphate/*metabolism , Methionine/*metabolism , Nitrogenase/*metabolism, Azotobacter vinelandii/enzymology ; Nitrogenase/chemistry ; Circular Dichroism ; Electron Spin Resonance Spectroscopy ; Hydrolysis ; Models, Molecular ; Protein Binding ; Protein Conformation ; Substrate Specificity |
| Περίληψη: | A variant Fe protein has been created at the completely conserved residue methionine 156 by changing it to cysteine. The Azotobacter vinelandii strain expressing M156C is unable to grow under nitrogen-fixing conditions, and the purified protein cannot support substrate reduction in vitro. This mutation has an effect on the Fe protein's ability to undergo the MgATP-induced conformational change as evidenced by the fact that M156C is chelated in the presence of MgATP with a lower observed rate than wild-type. While the electron paramagnetic resonance spectra of this protein are similar to those of the wild-type Fe protein, the circular dichroism spectrum is markedly different in the presence of MgATP, showing that the conformation adopted by M156C following nucleotide binding is different from the wild-type conformation. Although competition activity and chelation assays show that this Fe protein can still form a complex with the MoFe protein, this altered conformation only supports MgATP hydrolysis at 1% the rate of wild-type Fe protein. A model based on x-ray crystallographic information is presented to explain the importance of Met-156 in stabilization of the correct conformation of the Fe protein via critical interactions of the residue with Asp-43 and nucleotide in the other subunit. |
| Grant Information: | GM-45209 United States GM NIGMS NIH HHS |
| Substance Nomenclature: | 8L70Q75FXE (Adenosine Triphosphate) AE28F7PNPL (Methionine) EC 1.- (Oxidoreductases) EC 1.18.6.1 (Nitrogenase) EC 1.18.6.1 (nitrogenase reductase) |
| Entry Date(s): | Date Created: 19981029 Date Completed: 19981210 Latest Revision: 20210209 |
| Update Code: | 20260130 |
| DOI: | 10.1074/jbc.273.45.29678 |
| PMID: | 9792679 |
| Βάση Δεδομένων: | MEDLINE |
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