1e5m

From Proteopedia

Revision as of 14:00, 5 November 2007

BETA KETOACYL ACYL CARRIER PROTEIN SYNTHASE II (KASII) FROM SYNECHOCYSTIS SP.

Overview

Condensing enzymes, catalyzing the formation of carbon-carbon bonds in, several biosynthetic pathways, have lately been recognized as potential, drug targets against cancer and tuberculosis, as crucial for combinatorial, biosynthesis of antibiotics and related compounds, and as determinants of, plant oil composition. beta-Ketoacyl-ACP synthases (KAS) are the, condensing enzymes present in the fatty acid biosynthesis pathway and are, able to elongate an acyl chain bound to either co-enzyme A (CoA) or acyl, carrier protein (ACP) with a two-carbon unit derived from malonyl-ACP., Several isoforms of KAS with different substrate specificity are present, in most species. We have determined the crystal structure of KAS II from, Synechocystis sp. PCC 6803 to 1.54 A resolution giving a detailed, description of the active site geometry. In order to analyze the, structure-function relationships in this class of enzymes in more detail, we have compared all presently known three-dimensional structures of, condensing enzymes from different pathways. The comparison reveals that, these enzymes can be divided into three structural and functional classes., This classification can be related to variations in the catalytic, mechanism and the set of residues in the catalytic site, e.g. due to, differences in the nature of the second substrate providing the two-carbon, elongation unit. The variation in the acyl-carrier (ACP or CoA), specificity might also be connected to this classification and residues, involved in ACP binding in structure class 2 can be suggested based on the, comparison. Finally, the two subunits in the dimer contribute differently, to formation of the substrate binding-pocket in the three structural, classes.

About this Structure

1E5M is a Single protein structure of sequence from Synechocystis sp.. Active as Beta-ketoacyl-acyl-carrier-protein synthase I, with EC number 2.3.1.41 Structure known Active Site: CYS. Full crystallographic information is available from OCA.

Reference

The crystal structure of beta-ketoacyl-acyl carrier protein synthase II from Synechocystis sp. at 1.54 A resolution and its relationship to other condensing enzymes., Moche M, Dehesh K, Edwards P, Lindqvist Y, J Mol Biol. 2001 Jan 19;305(3):491-503. PMID:11152607

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