Open AccessExpression, purification and preliminary X‐ray diffraction analysis of a ketoreductase from a type II polyketide synthase
Author(s) -
Teartasin Watchrra,
Limpkin Claire,
Glod Frank,
Spencer James,
Cox Russell J.,
Simpson Thomas J.,
Crosby John,
Crump Matthew P.,
Hadfield Andrea T.
Publication year - 2004
Publication title -
acta crystallographica section d
Language(s) - English
Resource type - Journals
ISSN - 1399-0047
DOI - 10.1107/s0907444904007905
Subject(s) - polyketide , streptomyces coelicolor , polyketide synthase , stereochemistry , chemistry , streptomyces , biosynthesis , enzyme , biochemistry , biology , bacteria , genetics
Polyketide metabolites produced by bacteria and other organisms include antibiotics, anticancer and antifungal compounds. In type II polyketide synthesis, three enzymes are sufficient to form a polyketide product of the requisite chain length, although the fidelity of the first cyclization is variable. Addition of ketoreductase (KR) to this system results in the formation of a product with correct cyclization and reduction. This paper reports the cloning of the Streptomyces coelicolor actIII ORF5 gene that codes for the ketoreductase. The 261‐amino‐acid protein has been overexpressed with a 20‐residue His tag, purified by affinity chromatography and crystallized in space group P 3 2 21, with unit‐cell parameters a = b = 103.9, c = 123.1 Å. The crystals diffract to 2.5 Å resolution. A complete data set has been collected and structure solution and refinement is under way.