title: Localization of the ActIII actinorhodin polyketide ketoreductase to the cell wall.
abstract: Structurally diverse polyketides provide a rich reservoir of bioactive molecules. Actinorhodin, a model aromatic polyketide, is synthesized by minimal type II polyketide synthase and tailoring enzymes. The ActIII actinorhodin ketoreductase is a key tailoring enzyme in actinorhodin biosynthesis. With purified antibodies against actinorhodin polyketide synthase alpha subunit (KSalpha) and ketoreductase, we conducted systematic localization experiments of the two proteins in Streptomyces coelicolor subproteomes. The results support the membrane location of KSalpha and cell-wall location of ketoreductase. Considering previous evidence that some other tailoring enzymes of actinorhodin biosynthesis may be located outside the cytoplasm, a picture is emerging of an extensive role for extracellular biochemistry in the synthesis of type II polyketide antibiotic.
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Xin-Ping
authors.initials: XP
authors.lastname: Xu
authors.forename: Zhi-Jun
authors.initials: ZJ
authors.lastname: Wang
authors.forename: Ke-Qiang
authors.initials: KQ
authors.lastname: Fan
authors.forename: Sheng-Lan
authors.initials: SL
authors.lastname: Wang
authors.forename: Cui-Juan
authors.initials: CJ
authors.lastname: Jia
authors.forename: Hui
authors.initials: H
authors.lastname: Han
authors.forename: Eswar
authors.initials: E
authors.lastname: Ramalingam
authors.forename: Ke-Qian
authors.initials: KQ
authors.lastname: Yang
mesh_terms: D000429:Alcohol Oxidoreductases / Q000378:metabolism*; D000906:Antibodies / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism*; D002473:Cell Wall / Q000378:metabolism*; D002477:Cells / Q000187:drug effects; D003902:Detergents / Q000378:metabolism; D015870:Gene Expression; D009113:Muramidase / Q000494:pharmacology; D021122:Protein Subunits / Q000378:metabolism; D048372:Streptomyces coelicolor / Q000201:enzymology* / Q000235:genetics
chemical_list: D000906:Antibodies; D001426:Bacterial Proteins; D003902:Detergents; D021122:Protein Subunits; D000429:Alcohol Oxidoreductases; C062921:actIII protein, Streptomyces coelicolor; D009113:Muramidase