1fhl

From Proteopedia

CRYSTAL STRUCTURE OF BETA-1,4-GALACTANASE FROM ASPERGILLUS ACULEATUS AT 293K

Overview

The three-dimensional structure of Aspergillus aculeatus beta-1,4-galactanase (AAGAL), an enzyme involved in pectin degradation, has been determined by multiple isomorphous replacement to 2.3 and 1.8 A resolution at 293 and 100 K, respectively. It represents the first known structure for a polysaccharidase with this specificity and for a member of glycoside hydrolase family 53 (GH-53). The enzyme folds into a (beta/alpha)(8) barrel with the active site cleft located at the C-terminal side of the barrel consistent with the classification of GH-53 in clan GH-A, a superfamily of enzymes with common fold and catalytic machinery but diverse specificities. Putative substrate-enzyme interactions were elucidated by modeling of beta-1,4-linked galactobioses into the possible substrate binding subsites. The structure and modeling studies identified five potential subsites for the binding of galactans, of which one is a pocket suited for accommodating the arabinan side chain in arabinogalactan, one of the natural substrates. A comparison with the substrate binding grooves of other Clan GH-A enzymes suggests that shape complementarity is crucial in determining the specificity of polysaccharidases.

About this Structure

1FHL is a Single protein structure of sequence from Aspergillus aculeatus. Full crystallographic information is available from OCA.

Reference

Aspergillus aculeatus beta-1,4-galactanase: substrate recognition and relations to other glycoside hydrolases in clan GH-A., Ryttersgaard C, Lo Leggio L, Coutinho PM, Henrissat B, Larsen S, Biochemistry. 2002 Dec 24;41(51):15135-43. PMID:12484750

Page seeded by OCA on Thu Mar 20 11:09:18 2008