2zcf: Difference between revisions

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==Overview==

Nitrile hydratase (NHase) from Rhodococcus sp. N771 is a non-heme iron, enzyme having post-translationally modified cysteine ligands, alphaCys112-SO2H and alphaCys114-SOH. We replaced alphaGln90, which is, conserved in all known NHases and involved in the hydrogen-bond network, around the catalytic center, with glutamic acid or asparagine. The kcat of, alphaQ90E and alphaQ90N mutants decreased to 24% and 5% that of wild type, respectively, but the effect of mutations on Km was not very significant., In both mutants, the alphaCys114-SOH modification appeared to be, responsible for the catalysis as in native NHase. We crystallized the, nitrosylated alphaQ90N mutant and determined its structure at a resolution, of 1.43 A. The structure was basically identical to that of native, nitrosylated NHase except for the mutated site and its vicinity. The, structural difference between native and alphaQ90N mutant NHases suggested, the importance of the hydrogen bond networks between alphaGln90 and the, iron center for the catalytic activity.

Nitrile hydratase (NHase) from Rhodococcus sp. N771 is a non-heme iron enzyme having post-translationally modified cysteine ligands, alphaCys112-SO2H and alphaCys114-SOH. We replaced alphaGln90, which is conserved in all known NHases and involved in the hydrogen-bond network around the catalytic center, with glutamic acid or asparagine. The kcat of alphaQ90E and alphaQ90N mutants decreased to 24% and 5% that of wild type respectively, but the effect of mutations on Km was not very significant. In both mutants, the alphaCys114-SOH modification appeared to be responsible for the catalysis as in native NHase. We crystallized the nitrosylated alphaQ90N mutant and determined its structure at a resolution of 1.43 A. The structure was basically identical to that of native nitrosylated NHase except for the mutated site and its vicinity. The structural difference between native and alphaQ90N mutant NHases suggested the importance of the hydrogen bond networks between alphaGln90 and the iron center for the catalytic activity.

==About this Structure==

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[[Category: Nakayama, H.]]

[[Category: Odaka, M.]]

[[Category: RSGI, RIKEN.Structural.Genomics/Proteomics.Initiative.]]

[[Category: RSGI, RIKEN Structural Genomics/Proteomics Initiative.]]

[[Category: Takarada, H.]]

[[Category: Ueda, S.]]

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[[Category: structural genomics]]

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@@ Line 4: / Line 4: @@
 ==Overview==
-Nitrile hydratase (NHase) from Rhodococcus sp. N771 is a non-heme iron, enzyme having post-translationally modified cysteine ligands, alphaCys112-SO2H and alphaCys114-SOH. We replaced alphaGln90, which is, conserved in all known NHases and involved in the hydrogen-bond network, around the catalytic center, with glutamic acid or asparagine. The kcat of, alphaQ90E and alphaQ90N mutants decreased to 24% and 5% that of wild type, respectively, but the effect of mutations on Km was not very significant., In both mutants, the alphaCys114-SOH modification appeared to be, responsible for the catalysis as in native NHase. We crystallized the, nitrosylated alphaQ90N mutant and determined its structure at a resolution, of 1.43 A. The structure was basically identical to that of native, nitrosylated NHase except for the mutated site and its vicinity. The, structural difference between native and alphaQ90N mutant NHases suggested, the importance of the hydrogen bond networks between alphaGln90 and the, iron center for the catalytic activity.
+Nitrile hydratase (NHase) from Rhodococcus sp. N771 is a non-heme iron enzyme having post-translationally modified cysteine ligands, alphaCys112-SO2H and alphaCys114-SOH. We replaced alphaGln90, which is conserved in all known NHases and involved in the hydrogen-bond network around the catalytic center, with glutamic acid or asparagine. The kcat of alphaQ90E and alphaQ90N mutants decreased to 24% and 5% that of wild type respectively, but the effect of mutations on Km was not very significant. In both mutants, the alphaCys114-SOH modification appeared to be responsible for the catalysis as in native NHase. We crystallized the nitrosylated alphaQ90N mutant and determined its structure at a resolution of 1.43 A. The structure was basically identical to that of native nitrosylated NHase except for the mutated site and its vicinity. The structural difference between native and alphaQ90N mutant NHases suggested the importance of the hydrogen bond networks between alphaGln90 and the iron center for the catalytic activity.
 ==About this Structure==
@@ Line 21: / Line 21: @@
 [[Category: Nakayama, H.]]
 [[Category: Odaka, M.]]
-[[Category: RSGI, RIKEN.Structural.Genomics/Proteomics.Initiative.]]
+[[Category: RSGI, RIKEN Structural Genomics/Proteomics Initiative.]]
 [[Category: Takarada, H.]]
 [[Category: Ueda, S.]]
@@ Line 43: / Line 43: @@
 [[Category: structural genomics]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Jan 23 12:11:25 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:01:24 2008''