1fb1: Difference between revisions

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==Overview==

The crystal structure of recombinant human GTP cyclohydrolase I was solved, by Patterson search methods by using the coordinates of the Escherichia, coli enzyme as a model. The human as well as bacterial enzyme were shown, to contain an essential zinc ion coordinated to a His side chain and two, thiol groups in each active site of the homodecameric enzymes that had, escaped detection during earlier studies of the E. coli enzyme. The zinc, ion is proposed to generate a hydroxyl nucleophile for attack of imidazole, ring carbon atom eight of the substrate, GTP. It may also be involved in, the hydrolytic release of formate from the intermediate, 2-amino-5-formylamino-6-ribosylamino-4(3H)-pyrimidinone 5'-triphosphate, and in the consecutive Amadori rearrangement of the ribosyl moiety.

The crystal structure of recombinant human GTP cyclohydrolase I was solved by Patterson search methods by using the coordinates of the Escherichia coli enzyme as a model. The human as well as bacterial enzyme were shown to contain an essential zinc ion coordinated to a His side chain and two thiol groups in each active site of the homodecameric enzymes that had escaped detection during earlier studies of the E. coli enzyme. The zinc ion is proposed to generate a hydroxyl nucleophile for attack of imidazole ring carbon atom eight of the substrate, GTP. It may also be involved in the hydrolytic release of formate from the intermediate, 2-amino-5-formylamino-6-ribosylamino-4(3H)-pyrimidinone 5'-triphosphate, and in the consecutive Amadori rearrangement of the ribosyl moiety.

==Disease==

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[[Category: phosphorylation]]

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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:36:47 2008''

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@@ Line 4: / Line 4: @@
 ==Overview==
-The crystal structure of recombinant human GTP cyclohydrolase I was solved, by Patterson search methods by using the coordinates of the Escherichia, coli enzyme as a model. The human as well as bacterial enzyme were shown, to contain an essential zinc ion coordinated to a His side chain and two, thiol groups in each active site of the homodecameric enzymes that had, escaped detection during earlier studies of the E. coli enzyme. The zinc, ion is proposed to generate a hydroxyl nucleophile for attack of imidazole, ring carbon atom eight of the substrate, GTP. It may also be involved in, the hydrolytic release of formate from the intermediate, 2-amino-5-formylamino-6-ribosylamino-4(3H)-pyrimidinone 5'-triphosphate, and in the consecutive Amadori rearrangement of the ribosyl moiety.
+The crystal structure of recombinant human GTP cyclohydrolase I was solved by Patterson search methods by using the coordinates of the Escherichia coli enzyme as a model. The human as well as bacterial enzyme were shown to contain an essential zinc ion coordinated to a His side chain and two thiol groups in each active site of the homodecameric enzymes that had escaped detection during earlier studies of the E. coli enzyme. The zinc ion is proposed to generate a hydroxyl nucleophile for attack of imidazole ring carbon atom eight of the substrate, GTP. It may also be involved in the hydrolytic release of formate from the intermediate, 2-amino-5-formylamino-6-ribosylamino-4(3H)-pyrimidinone 5'-triphosphate, and in the consecutive Amadori rearrangement of the ribosyl moiety.
 ==Disease==
@@ Line 35: / Line 35: @@
 [[Category: phosphorylation]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri Feb 15 15:46:46 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:36:47 2008''