title: The polyketide cyclase RemF from Streptomyces resistomycificus contains an unusual octahedral zinc binding site.
abstract: RemF is a polyketide cyclase involved in the biosynthesis of the aromatic pentacyclic metabolite resistomycin in Streptomyces resistomycificus. The enzyme is a member of a structurally hitherto uncharacterized class of polyketide cyclases. The crystal structure of RemF was determined by SAD and refined to 1.2 A resolution. The enzyme subunit shows a beta-sandwich structure with a topology characteristic for the cupin fold. RemF contains a metal binding site located at the bottom of the predominantly hydrophobic active site cavity. A zinc ion is coordinated to four histidine side chains, and two water molecules in octahedral ligand sphere geometry, highly unusual for zinc binding sites in proteins.
authors: Department of Medical Biophysics and Biochemistry, Karolinska Institutet, Stockholm, Sweden.
authors: Laura
authors: L
authors: Silvennoinen
authors: Tatyana
authors: T
authors: Sandalova
authors: Gunter
authors: G
authors: Schneider
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D001580:Benzopyrenes / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D048630:Polyketide Synthases / Q000737:chemistry* / Q000235:genetics; D011487:Protein Conformation; D017510:Protein Folding; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics; D013302:Streptomyces / Q000201:enzymology*; D015032:Zinc / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D001580:Benzopyrenes; D021122:Protein Subunits; C018379:resistomycin; D048630:Polyketide Synthases; D015032:Zinc