1gk2: Difference between revisions

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==Overview==

Histidine ammonia-lyase requires a 4-methylidene-imidazole-5-one group, (MIO) that is produced autocatalytically by a cyclization and dehydration, step in a 3-residue loop of the polypeptide. The crystal structures of, three mutants have been established. Two mutants were inactive and failed, to form MIO, but remained unchanged elsewhere. The third mutant showed, very low activity and formed MIO, although it differed from an MIO-less, mutant only by an additional 329-C(beta) atom. This atom forms one, constraint during MIO formation, the other being the strongly connected, Asp145. An exploration of the conformational space of the MIO-forming loop, showed that the cyclization is probably enforced by a mechanic compression, in a late stage of chain folding and is catalyzed by a well-connected, internal water molecule. The cyclization of the respective 3-residue loop, of green fluorescent protein is likely to occur in a similar reaction.

Histidine ammonia-lyase requires a 4-methylidene-imidazole-5-one group (MIO) that is produced autocatalytically by a cyclization and dehydration step in a 3-residue loop of the polypeptide. The crystal structures of three mutants have been established. Two mutants were inactive and failed to form MIO, but remained unchanged elsewhere. The third mutant showed very low activity and formed MIO, although it differed from an MIO-less mutant only by an additional 329-C(beta) atom. This atom forms one constraint during MIO formation, the other being the strongly connected Asp145. An exploration of the conformational space of the MIO-forming loop showed that the cyclization is probably enforced by a mechanic compression in a late stage of chain folding and is catalyzed by a well-connected internal water molecule. The cyclization of the respective 3-residue loop of green fluorescent protein is likely to occur in a similar reaction.

==About this Structure==

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[[Category: Single protein]]

[[Category: Baedeker, M.]]

[[Category: Schulz, G.E.]]

[[Category: Schulz, G E.]]

[[Category: GOL]]

[[Category: SO4]]

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[[Category: lyase]]

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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:50:54 2008''

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@@ Line 4: / Line 4: @@
 ==Overview==
-Histidine ammonia-lyase requires a 4-methylidene-imidazole-5-one group, (MIO) that is produced autocatalytically by a cyclization and dehydration, step in a 3-residue loop of the polypeptide. The crystal structures of, three mutants have been established. Two mutants were inactive and failed, to form MIO, but remained unchanged elsewhere. The third mutant showed, very low activity and formed MIO, although it differed from an MIO-less, mutant only by an additional 329-C(beta) atom. This atom forms one, constraint during MIO formation, the other being the strongly connected, Asp145. An exploration of the conformational space of the MIO-forming loop, showed that the cyclization is probably enforced by a mechanic compression, in a late stage of chain folding and is catalyzed by a well-connected, internal water molecule. The cyclization of the respective 3-residue loop, of green fluorescent protein is likely to occur in a similar reaction.
+Histidine ammonia-lyase requires a 4-methylidene-imidazole-5-one group (MIO) that is produced autocatalytically by a cyclization and dehydration step in a 3-residue loop of the polypeptide. The crystal structures of three mutants have been established. Two mutants were inactive and failed to form MIO, but remained unchanged elsewhere. The third mutant showed very low activity and formed MIO, although it differed from an MIO-less mutant only by an additional 329-C(beta) atom. This atom forms one constraint during MIO formation, the other being the strongly connected Asp145. An exploration of the conformational space of the MIO-forming loop showed that the cyclization is probably enforced by a mechanic compression in a late stage of chain folding and is catalyzed by a well-connected internal water molecule. The cyclization of the respective 3-residue loop of green fluorescent protein is likely to occur in a similar reaction.
 ==About this Structure==
@@ Line 15: / Line 15: @@
 [[Category: Single protein]]
 [[Category: Baedeker, M.]]
-[[Category: Schulz, G.E.]]
+[[Category: Schulz, G E.]]
 [[Category: GOL]]
 [[Category: SO4]]
@@ Line 22: / Line 22: @@
 [[Category: lyase]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Feb  3 09:40:35 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:50:54 2008''