1gjw

From Proteopedia

proteopedia linkproteopedia link

spinqualitylabelsall models 1gjw, resolution 2.1Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

THERMOTOGA MARITIMA MALTOSYLTRANSFERASE COMPLEX WITH MALTOSE

Overview

Maltosyltransferase (MTase) from the hyperthermophile Thermotoga maritima, represents a novel maltodextrin glycosyltransferase acting on starch and, malto-oligosaccharides. It catalyzes the transfer of maltosyl units from, alpha-1,4-linked glucans or malto-oligosaccharides to other, alpha-1,4-linked glucans, malto-oligosaccharides or glucose. It belongs to, the glycoside hydrolase family 13, which represents a large group of, (beta/alpha)(8) barrel proteins sharing a similar active site structure., The crystal structures of MTase and its complex with maltose have been, determined at 2.4 A and 2.1 A resolution, respectively. MTase is a, homodimer, each subunit of which consists of four domains, two of which, are structurally homologous to those of other family 13 enzymes. The, catalytic core domain has the (beta/alpha)(8) barrel fold with the, active-site cleft formed at the C-terminal end of the barrel. Substrate, binding experiments have led to the location of two distinct, maltose-binding sites; one lies in the active-site cleft, covering, subsites -2 and -1; the other is located in a pocket adjacent to the, active-site cleft. The structure of MTase, together with the conservation, of active-site residues among family 13 glycoside hydrolases, are, consistent with a common double-displacement catalytic mechanism for this, enzyme. Analysis of maltose binding in the active site reveals that the, transfer of dextrinyl residues longer than a maltosyl unit is prevented by, termination of the active-site cleft after the -2 subsite by the, side-chain of Lys151 and the stretch of residues 314-317, providing an, explanation for the strict transfer specificity of MTase.

About this Structure

1GJW is a Single protein structure of sequence from Thermotoga maritima with MAL, GLC and PO4 as ligands. Known structural/functional Sites: and . Full crystallographic information is available from OCA.

Reference

The crystal structure of Thermotoga maritima maltosyltransferase and its implications for the molecular basis of the novel transfer specificity., Roujeinikova A, Raasch C, Burke J, Baker PJ, Liebl W, Rice DW, J Mol Biol. 2001 Sep 7;312(1):119-31. PMID:11545590

Page seeded by OCA on Tue Dec 18 15:21:56 2007