2bv4

From Proteopedia

Revision as of 15:44, 5 November 2007

1.0A STRUCTURE OF CHROMOBACTERIUM VIOLACEUM LECTIN IN COMPLEX WITH ALPHA-METHYL-MANNOSIDE

Overview

The purple pigmented bacterium Chromobacterium violaceum is a dominant, component of tropical soil microbiota that can cause rare but fatal, septicaemia in humans. Its sequenced genome provides insight into the, abundant potential of this organism for biotechnological and, pharmaceutical applications and allowed an ORF encoding a protein that is, 60% identical to the fucose binding lectin (PA-IIL) from Pseudomonas, aeruginosa and the mannose binding lectin (RS-IIL) from Ralstonia, solanacearum to be identified. The lectin, CV-IIL, has recently been, purified from C. violaceum [Zinger-Yosovich, K., Sudakevitz, D., Imberty, A., Garber, N. C., and Gilboa-Garber, N. (2006) Microbiology 152, 457-463], and has been confirmed to be a tetramer with subunit size of 11.86 kDa and, a binding preference for fucose. We describe here the cloning of CV-IIL, and its expression as a recombinant protein. A complete structure-function, characterization has been made in an effort to analyze the specificity and, affinity of CV-IIL for fucose and mannose. Crystal structures of CV-IIL, complexes with monosaccharides have yielded the molecular basis of the, specificity. Each monomer contains two close calcium cations that mediate, the binding of the monosaccharides, which occurs in different orientations, for fucose and mannose. The thermodynamics of binding has been analyzed by, titration microcalorimetry, giving dissociation constants of 1.7 and 19, microM for alpha-methyl fucoside and alpha-methyl mannoside, respectively., Further analysis demonstrated a strongly favorable entropy term that is, unusual in carbohydrate binding. A comparison with both PA-IIL and RS-IIL, which have binding preferences for fucose and mannose, respectively, yielded insights into the monosaccharide specificity of this important, class of soluble bacterial lectins.

About this Structure

2BV4 is a Single protein structure of sequence from Chromobacterium violaceum with MMA and CA as ligands. Structure known Active Site: AC1. Full crystallographic information is available from OCA.

Reference

Unusual entropy-driven affinity of Chromobacterium violaceum lectin CV-IIL toward fucose and mannose., Pokorna M, Cioci G, Perret S, Rebuffet E, Kostlanova N, Adam J, Gilboa-Garber N, Mitchell EP, Imberty A, Wimmerova M, Biochemistry. 2006 Jun 20;45(24):7501-10. PMID:16768446

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