1hcu
From Proteopedia
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ALPHA-1,2-MANNOSIDASE FROM TRICHODERMA REESEI
Overview
The process of N-glycosylation of eukaryotic proteins involves a range of host enzymes that delete or add saccharide monomers. While endoplasmic reticulum (E.R.) mannosidases cleave only one mannose to produce the Man8B isomer, an alpha-1,2-mannosidase from Trichoderma reesei can sequentially cleave all four 1,2-linked mannose sugars from a Man(9)GlcNAc(2) oligosaccharide, a feature reminiscent of the activity of Golgi mannosidases. We now report the structure of the T. reesei enzyme at 2.37 A resolution. The enzyme folds as an (alpha alpha)(7) barrel. The substrate-binding site of the T. reesei mannosidase differs appreciably from the Saccharomyces cerevisiae enzyme. In the former, shorter loops at the surface allow substrate protein to come closer to the catalytic site. There is more internal space available, so that different oligosaccharide conformations are sterically allowed in the T. reesei alpha-1,2-mannosidase.
About this Structure
1HCU is a Single protein structure of sequence from Hypocrea jecorina with and as ligands. Active as Mannosyl-oligosaccharide 1,2-alpha-mannosidase, with EC number 3.2.1.113 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Trichoderma reesei alpha-1,2-mannosidase: structural basis for the cleavage of four consecutive mannose residues., Van Petegem F, Contreras H, Contreras R, Van Beeumen J, J Mol Biol. 2001 Sep 7;312(1):157-65. PMID:11545593
Page seeded by OCA on Thu Feb 21 12:59:55 2008
