2iv2: Difference between revisions
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==Overview== | ==Overview== | ||
Re-evaluation of the crystallographic data of the molybdenum-containing E., coli formate dehydrogenase H (Boyington et al. Science 275:1305-1308, 1997), reported in two redox states, reveals important structural, differences for the formate-reduced form, with large implications for the, reaction mechanism proposed in that work. We have re-refined the reduced, structure with revised protocols and found substantial rearrangement in, some parts of it. The original model is essentially correct but an, important loop close to the molybdenum active site was mistraced, and, therefore, catalytic relevant residues were located in wrong positions. In, particular selenocysteine-140, a ligand of molybdenum in the original, work, and essential for catalysis, is no longer bound to the metal after, ... | Re-evaluation of the crystallographic data of the molybdenum-containing E., coli formate dehydrogenase H (Boyington et al. Science 275:1305-1308, 1997), reported in two redox states, reveals important structural, differences for the formate-reduced form, with large implications for the, reaction mechanism proposed in that work. We have re-refined the reduced, structure with revised protocols and found substantial rearrangement in, some parts of it. The original model is essentially correct but an, important loop close to the molybdenum active site was mistraced, and, therefore, catalytic relevant residues were located in wrong positions. In, particular selenocysteine-140, a ligand of molybdenum in the original, work, and essential for catalysis, is no longer bound to the metal after, reduction of the enzyme with formate. These results are incompatible with, the originally proposed reaction mechanism. On the basis of our new, interpretation, we have revised and proposed a new reaction mechanism, which reconciles the new X-ray model with previous biochemical and, extended X-ray absorption fine structure data. | ||
==About this Structure== | ==About this Structure== | ||
2IV2 is a | 2IV2 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ] with SF4, 2MD, MGD, MO and S as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Formate_dehydrogenase Formate dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.2.1.2 1.2.1.2] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2IV2 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: selenocysteine]] | [[Category: selenocysteine]] | ||
''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 13:47:03 2007'' | ||
