1k6e

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spinqualitylabelsall models 1k6e, resolution 1.85Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

COMPLEX OF HYDROLYTIC HALOALKANE DEHALOGENASE LINB FROM SPHINGOMONAS PAUCIMOBILIS UT26 WITH 1,2-PROPANEDIOL (PRODUCT OF DEHALOGENATION OF 1,2-DIBROMOPROPANE) AT 1.85A

Overview

The haloalkane dehalogenases are detoxifying enzymes that convert a broad, range of halogenated substrates to the corresponding alcohols. Complete, crystal structures of haloalkane dehalogenase from Sphingomonas, paucimobilis UT26 (LinB), and complexes of LinB with, 1,2-propanediol/1-bromopropane-2-ol and 2-bromo-2-propene-1-ol, products, of debromination of 1,2-dibromopropane and 2,3-dibromopropene, respectively, were determined from 1.8 A resolution X-ray diffraction, data. Published structures of native LinB and its complex with, 1,3-propanediol [Marek et al. (2000) Biochemistry 39, 14082-14086] were, reexamined. The full and partial debromination of 1,2-dibromopropane and, 2,3-dibromopropene, respectively, conformed to the observed general trend, that the sp(3)-hybridized carbon is the predominant electrophilic site for, the S(N)2 bimolecular nucleophilic substitution in dehalogenation, reaction. The 2-bromo-2-propene-1-ol product of 2,3-dibromopropene, dehalogenation in crystal was positively identified by the gas, chromatography-mass spectroscopy (GC-MS) technique. The 1,2-propanediol, and 1-bromopropane-2-ol products of 1,2-dibromopropane dehalogenation in, crystal were also supported by the GC-MS identification. Comparison of, native LinB with its complexes showed high flexibility of residues, 136-157, in particular, Asp146 and Glu147, from the cap domain helices, alpha(4) and alpha(5)('). Those residues were shifted mainly in direction, toward the ligand molecules in the complex structures. It seems the cap, domain moves nearer to the core squeezing substrate into the active center, closer to the catalytic triad. This also leads to slight contraction of, the whole complex structures. The flexibility detected by crystallographic, analysis is in remarkable agreement with flexibility observed by molecular, dynamic simulations.

About this Structure

1K6E is a Single protein structure of sequence from Sphingomonas paucimobilis with BR, CL, MG, PGO and 1BP as ligands. Active as Haloalkane dehalogenase, with EC number 3.8.1.5 Full crystallographic information is available from OCA.

Reference

Haloalkane dehalogenase LinB from Sphingomonas paucimobilis UT26: X-ray crystallographic studies of dehalogenation of brominated substrates., Streltsov VA, Prokop Z, Damborsky J, Nagata Y, Oakley A, Wilce MC, Biochemistry. 2003 Sep 2;42(34):10104-12. PMID:12939138

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