2ber

From Proteopedia

Revision as of 14:30, 30 October 2007

Y370G ACTIVE SITE MUTANT OF THE SIALIDASE FROM MICROMONOSPORA VIRIDIFACIENS IN COMPLEX WITH BETA-NEU5AC (SIALIC ACID).

Overview

Mutagenesis of the conserved tyrosine (Y370) of the Micromonospora, viridifaciens sialidase to small amino acids changes the mechanism of, catalysis from retention of anomeric configuration to inversion [Watson, J. N., et al. (2003) Biochemistry 42, 12682-12690]. For the Y370G mutant, enzyme-catalyzed hydrolysis of a series of aryl sialosides and, 3'-sialyllactose, the derived Bronsted parameters (beta(lg)) on k(cat) and, k(cat)/K(m) are -0.63 +/- 0.05 and -0.80 +/- 0.08, respectively. Thus, for, the Y370G enzyme, glycosidic C-O bond cleavage is rate-determining., Analysis of the activity of the Y370G mutant and wild-type enzymes against, a substrate [3,4-dihydro-2H-pyrano[3,2-c]pyridinium, alpha-d-N-acetylneuraminide (DHP-alphaNeu5Ac)] whose hydrolysis cannot be, accelerated by acid ... [(full description)]

About this Structure

2BER is a [Single protein] structure of sequence from [Micromonospora viridifaciens] with SLB and NA as [ligands]. Active as [Exo-alpha-sialidase], with EC number [3.2.1.18]. Structure known Active Site: AC1. Full crystallographic information is available from [OCA].

Reference

Structure and mechanism of action of an inverting mutant sialidase., Newstead S, Watson JN, Knoll TL, Bennet AJ, Taylor G, Biochemistry. 2005 Jun 28;44(25):9117-22. PMID:15966735

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