2ebn

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spinqualitylabelsall models 2ebn, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

CRYSTAL STRUCTURE OF ENDO-BETA-N-ACETYLGLUCOSAMINIDASE F1, AN ALPHA(SLASH)BETA-BARREL ENZYME ADAPTED FOR A COMPLEX SUBSTRATE

Overview

Endo-beta-N-acetylglucosaminidase F1 (Endo F1) is an endoglycosidase, secreted by Flavobacterium meningosepticum, that cleaves asparagine-linked, oligosaccharides after the first N-acetylglucosamine residue. The enzyme, is selective for high-mannose oligosaccharide chains. The crystal, structure of Endo F1 has been determined at 2.0-A resolution. The, molecular fold consists of a highly irregular alpha/beta-barrel, a, commonly observed motif consisting of a cyclic 8-fold repeat of, beta-strand/loop/alpha-helix units with an eight-stranded parallel, beta-barrel at the center. Endo F1 lacks two of the alpha-helices, those, of units 5 and 6. Instead, the links after beta-strands 5 and 6 consist of, a short turn followed by a section in an extended conformation that, replaces the helix and a long loop at the bottom of the molecule. The, absence of any excursion on top of the molecule following beta-strands 5, and 6 results in a pronounced depression in the rim of the barrel. This, depression forms one end of a shallow cleft that runs across the surface, of the molecule, over the core of the beta-barrel to the area between the, loops of units 1 and 2. The active site residues, Asp130 and Glu132, are, located at the carboxyl end of beta-strand 4 and extend into this cleft., These residues are surrounded by several tyrosine residues. The cleft area, formed by loops 1 and 2 is lined with polar residues, mainly asparagines., The latter area is thought to be responsible for oligosaccharide binding, and recognition while the protein moiety of the substrate would be located, outside the molecule but adjacent to the area of loops 5 and 6.(ABSTRACT, TRUNCATED AT 250 WORDS)

About this Structure

2EBN is a Single protein structure of sequence from Elizabethkingia meningoseptica with ZN as ligand. Active as Mannosyl-glycoprotein endo-beta-N-acetylglucosaminidase, with EC number 3.2.1.96 Full crystallographic information is available from OCA.

Reference

Crystal structure of endo-beta-N-acetylglucosaminidase F1, an alpha/beta-barrel enzyme adapted for a complex substrate., Van Roey P, Rao V, Plummer TH Jr, Tarentino AL, Biochemistry. 1994 Nov 29;33(47):13989-96. PMID:7947807

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