3c48
From Proteopedia
Structure of the retaining glycosyltransferase MshA: The first step in mycothiol biosynthesis. Organism: Corynebacterium glutamicum- APO (OPEN) structure.
Overview
The glycosyltransferase termed MshA catalyzes the transfer of N-acetylglucosamine from UDP-N-acetylglucosamine to 1-l-myo-inositol-1-phosphate in the first committed step of mycothiol biosynthesis. The structure of MshA from Corynebacterium glutamicum was determined both in the absence of substrates and in a complex with UDP and 1-l-myo-inositol-1-phosphate. MshA belongs to the GT-B structural family whose members have a two-domain structure with both domains exhibiting a Rossman-type fold. Binding of the donor sugar to the C-terminal domain produces a 97 degrees rotational reorientation of the N-terminal domain relative to the C-terminal domain, clamping down on UDP and generating the binding site for 1-l-myo-inositol-1-phosphate. The structure highlights the residues important in binding of UDP-N-acetylglucosamine and 1-l-myo-inositol-1-phosphate. Molecular models of the ternary complex suggest a mechanism in which the beta-phosphate of the substrate, UDP-N-acetylglucosamine, promotes the nucleophilic attack of the 3-hydroxyl group of 1-l-myo-inositol-1-phosphate while at the same time promoting the cleavage of the sugar nucleotide bond.
About this Structure
3C48 is a Single protein structure of sequence from Corynebacterium glutamicum. Full crystallographic information is available from OCA.
Reference
Structural and Enzymatic Analysis of MshA from Corynebacterium glutamicum: SUBSTRATE-ASSISTED CATALYSIS., Vetting MW, Frantom PA, Blanchard JS, J Biol Chem. 2008 Jun 6;283(23):15834-44. Epub 2008 Apr 4. PMID:18390549 Page seeded by OCA on Wed Jun 18 12:21:26 2008
