2c8v
From Proteopedia
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==Overview== | ==Overview== | ||
| - | In the present work, determination of the structure of the nitrogenase Leu, 127 deletion variant Fe protein with MgATP bound is presented, along with, density functional theory calculations, to provide insights into the roles, of MgATP in the nitrogenase reaction mechanism. Comparison of the, MgATP-bound structure of this Fe protein to the nucleotide-free form, indicates that the binding of MgATP does not alter the overall structure, of the variant significantly with only small differences in the, conformation of amino acids in direct contact with the two bound MgATP, molecules being seen. The earlier observation of splitting of the [4Fe-4S], cluster into two [2Fe-2S] clusters was observed to be unaltered upon, binding MgATP. Density functional theory was used to probe the assignment, of . | + | In the present work, determination of the structure of the nitrogenase Leu, 127 deletion variant Fe protein with MgATP bound is presented, along with, density functional theory calculations, to provide insights into the roles, of MgATP in the nitrogenase reaction mechanism. Comparison of the, MgATP-bound structure of this Fe protein to the nucleotide-free form, indicates that the binding of MgATP does not alter the overall structure, of the variant significantly with only small differences in the, conformation of amino acids in direct contact with the two bound MgATP, molecules being seen. The earlier observation of splitting of the [4Fe-4S], cluster into two [2Fe-2S] clusters was observed to be unaltered upon, binding MgATP. Density functional theory was used to probe the assignment, of ligands to the two [2Fe-2S] rhombs. The Mg(2+) environment in the, MgATP-bound structure of the Leu127 deletion Fe protein is similar to that, observed for the Fe protein in the nitrogenase Fe protein: MoFe protein, complex stabilized by MgADP and tetrafluoroaluminate suggesting that large, scale conformational change implicated for the Fe protein may not be, mediated by changes in the Mg(2+) coordination. The results presented here, indicated that MgATP may enhance the stability of an open conformation and, prohibit intersubunit interactions, which have been implicated in, promoting nucleotide hydrolysis. This could be critical to the tight, control of MgATP hydrolysis observed within the nitrogenase complex and, may be important for maintaining unidirectional electron flow toward, substrate reduction. |
==About this Structure== | ==About this Structure== | ||
| - | 2C8V is a | + | 2C8V is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Azotobacter_vinelandii Azotobacter vinelandii] with MG, FS1 and ATP as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Nitrogenase Nitrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.18.6.1 1.18.6.1] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2C8V OCA]. |
==Reference== | ==Reference== | ||
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[[Category: oxidoreductase]] | [[Category: oxidoreductase]] | ||
| - | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 15:26:09 2007'' |
Revision as of 13:20, 5 November 2007
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INSIGHTS INTO THE ROLE OF NUCLEOTIDE-DEPENDENT CONFORMATIONAL CHANGE IN NITROGENASE CATALYSIS: STRUCTURAL CHARACTERIZATION OF THE NITROGENASE FE PROTEIN LEU127 DELETION VARIANT WITH BOUND MGATP
Overview
In the present work, determination of the structure of the nitrogenase Leu, 127 deletion variant Fe protein with MgATP bound is presented, along with, density functional theory calculations, to provide insights into the roles, of MgATP in the nitrogenase reaction mechanism. Comparison of the, MgATP-bound structure of this Fe protein to the nucleotide-free form, indicates that the binding of MgATP does not alter the overall structure, of the variant significantly with only small differences in the, conformation of amino acids in direct contact with the two bound MgATP, molecules being seen. The earlier observation of splitting of the [4Fe-4S], cluster into two [2Fe-2S] clusters was observed to be unaltered upon, binding MgATP. Density functional theory was used to probe the assignment, of ligands to the two [2Fe-2S] rhombs. The Mg(2+) environment in the, MgATP-bound structure of the Leu127 deletion Fe protein is similar to that, observed for the Fe protein in the nitrogenase Fe protein: MoFe protein, complex stabilized by MgADP and tetrafluoroaluminate suggesting that large, scale conformational change implicated for the Fe protein may not be, mediated by changes in the Mg(2+) coordination. The results presented here, indicated that MgATP may enhance the stability of an open conformation and, prohibit intersubunit interactions, which have been implicated in, promoting nucleotide hydrolysis. This could be critical to the tight, control of MgATP hydrolysis observed within the nitrogenase complex and, may be important for maintaining unidirectional electron flow toward, substrate reduction.
About this Structure
2C8V is a Single protein structure of sequence from Azotobacter vinelandii with MG, FS1 and ATP as ligands. Active as Nitrogenase, with EC number 1.18.6.1 Structure known Active Site: AC1. Full crystallographic information is available from OCA.
Reference
Insights into the role of nucleotide-dependent conformational change in nitrogenase catalysis: Structural characterization of the nitrogenase Fe protein Leu127 deletion variant with bound MgATP., Sen S, Krishnakumar A, McClead J, Johnson MK, Seefeldt LC, Szilagyi RK, Peters JW, J Inorg Biochem. 2006 May;100(5-6):1041-52. Epub 2006 Mar 3. PMID:16616373
Page seeded by OCA on Mon Nov 5 15:26:09 2007
Categories: Azotobacter vinelandii | Nitrogenase | Single protein | Johnson, M.K. | Krishnakumar, A. | Mcclead, J. | Peters, J.W. | Seefeldt, L.C. | Sen, S. | Szilagyi, R.K. | ATP | FS1 | MG | 4fe-4s | Atp-binding | Av2 | Fe protein | Iron | Iron-sulfur | Metal-binding | Mgadp | Nitrogen fixation | Nucleotide-binding | Oxidoreductase
