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spinqualitylabelsall models 1rya, resolution 1.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal Structure of the E. coli GDP-mannose mannosyl hydrolase in complex with GDP and MG

Overview

GDP-mannose glycosyl hydrolase (GDPMH) catalyzes the hydrolysis of, GDP-mannose and GDP-glucose to GDP and sugar by substitution with, inversion at C1 of the sugar. The enzyme has a modified Nudix motif and, requires one divalent cation for activity. The 1.3 A X-ray structure of, the GDPMH-Mg(2+)-GDP complex, together with kinetic, mutational, and NMR, data, suggests a mechanism for the GDPMH reaction. Several residues and, the divalent cation strongly promote the departure of the GDP leaving, group, supporting a dissociative mechanism. Comparison of the GDPMH, structure with that of a typical Nudix hydrolase suggests how sequence, changes result in the switch of catalytic activity from P-O bond cleavage, to C-O bond cleavage. Changes in the Nudix motif result in loss of binding, of at least one Mg(2+) ion, and shortening of a loop by 6 residues shifts, the catalytic base by approximately 10 A.

About this Structure

1RYA is a Single protein structure of sequence from Escherichia coli with MG, CL, GDP and TRS as ligands. Full crystallographic information is available from OCA.

Reference

Structure and mechanism of GDP-mannose glycosyl hydrolase, a Nudix enzyme that cleaves at carbon instead of phosphorus., Gabelli SB, Bianchet MA, Azurmendi HF, Xia Z, Sarawat V, Mildvan AS, Amzel LM, Structure. 2004 Jun;12(6):927-35. PMID:15274914

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