1w4z
From Proteopedia
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STRUCTURE OF ACTINORHODIN POLYKETIDE (ACTIII) REDUCTASE
Overview
We have determined the 2.5 angstroms crystal structure of an active, tetrameric Streptomyces coelicolor type II polyketide ketoreductase, (actIII) with its bound cofactor, NADP+. This structure shows a Rossman, dinucleotide binding fold characteristic of SDR enzymes. Of two subunits, in the crystallographic asymmetric unit, one is closed around the active, site. Formate is observed in the open subunit, indicating possible, carbonyl binding sites of the polyketide intermediate. Unlike previous, models we observe crystal contacts that may mimic the KR-ACP interactions, that may drive active site opening. Based on these observations, we have, constructed a model for ACP and polyketide binding. We propose that, binding of ACP triggers a conformational change from the closed to the, open, active form of the enzyme. The polyketide chain enters the active, site and reduction occurs. The model also suggests a general mechanism for, ACP recognition which is applicable to a range of protein families.
About this Structure
1W4Z is a Single protein structure of sequence from Streptomyces coelicolor with NAP and FMT as ligands. Structure known Active Site: AC1. Full crystallographic information is available from OCA.
Reference
The crystal structure of the actIII actinorhodin polyketide reductase: proposed mechanism for ACP and polyketide binding., Hadfield AT, Limpkin C, Teartasin W, Simpson TJ, Crosby J, Crump MP, Structure. 2004 Oct;12(10):1865-75. PMID:15458634
Page seeded by OCA on Mon Nov 5 15:42:23 2007
