1tyg
From Proteopedia
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Structure of the thiazole synthase/ThiS complex
Overview
Thiazole synthase is the key enzyme involved in the formation of the, thiazole moiety of thiamin pyrophosphate. We have determined the structure, of this enzyme in complex with ThiS, the sulfur carrier protein, at 3.15 A, resolution. Thiazole synthase is a tetramer with 222 symmetry. The monomer, is a (betaalpha)(8) barrel with similarities to the aldolase class 1 and, flavin mononucleotide dependent oxidoreductase and phosphate binding, superfamilies. The sulfur carrier protein (ThiS) is a compact protein with, a fold similar to that of ubiquitin. The structure allowed us to model the, substrate, deoxy-D-xylulose 5-phosphate (DXP), in the active site. This, model identified Glu98 and Asp182 as new active site residues likely to be, involved in the catalysis of thiazole formation. The function of these, residues was probed by mutagenesis experiments, which confirmed that both, residues are essential for thiazole formation and identified Asp182 as the, base involved in the deprotonation at C3 of the thiazole synthase DXP, imine. Comparison of the ThiS binding surface to the surface of ubiquitin, identified a conserved hydrophobic patch of unknown function on ubiquitin, that may be involved in complex formation between ubiquitin and one of its, binding partners.
About this Structure
1TYG is a Protein complex structure of sequences from Bacillus subtilis with PO4 as ligand. Full crystallographic information is available from OCA.
Reference
Thiamin biosynthesis in Bacillus subtilis: structure of the thiazole synthase/sulfur carrier protein complex., Settembre EC, Dorrestein PC, Zhai H, Chatterjee A, McLafferty FW, Begley TP, Ealick SE, Biochemistry. 2004 Sep 21;43(37):11647-57. PMID:15362849
Page seeded by OCA on Wed Nov 21 03:41:46 2007
