title: Identification of binding protein of virginiae butanolide C, an autoregulator in virginiamycin production, from Streptomyces virginiae.
abstract: In Streptomyces virginiae, production of virginiamycin is triggered by signal molecules named virginiae butanolide A, B or C (VB-A, B or C: Yamada, Y. et al. J. Antibiotics 40: 496-504, 1987). We have found a specific VB-C binding protein from S. virginiae, and characterized it by using a tritium-labeled VB-C analogue as a ligand. By equilibrium dialysis in the absence and presence of radio-inert VB-C, a crude extract from 1 g of wet mycelia specifically bound 3.5 pmol of [3H]VB. The binding disappeared after pronase digestion and showed ligand specificity toward cis VB-C (cis VB-C greater than trans VB-C much greater than A-factor type), indicating that binding was due to a cis VB-C specific binding protein. Scatchard analysis of the binding demonstrated a single class of high affinity binding sites (Kd 1.1 nM) and low number of the binding sites (30-40 sites/genome DNA). By gel filtration on Sephadex G-75 and molecular sieve HPLC, the binding protein was shown to have an Mr of about 20,000. These results indicate that the substance is a novel VB-C binding protein and suggest that it is a VB-receptor mediating the pleiotropic signal transmitted by VBs in S. virginiae.
authors.affiliation: Department of Fermentation Technology, Faculty of Engineering, Osaka University, Japan.
authors.forename: H S
authors.initials: HS
authors.lastname: Kim
authors.forename: T
authors.initials: T
authors.lastname: Nihira
authors.forename: H
authors.initials: H
authors.lastname: Tada
authors.forename: M
authors.initials: M
authors.lastname: Yanagimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Yamada
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives / Q000378:metabolism*; D000900:Anti-Bacterial Agents; D001665:Binding Sites; D002352:Carrier Proteins / Q000032:analysis* / Q000378:metabolism; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D005663:Furans / Q000378:metabolism*; D006706:Homeostasis; D008970:Molecular Weight; D011402:Pronase / Q000378:metabolism; D015398:Signal Transduction; D013302:Streptomyces / Q000032:analysis*; D014316:Tritium; D014769:Virginiamycin / Q000096:biosynthesis*
chemical_list: D000900:Anti-Bacterial Agents; D002352:Carrier Proteins; D005663:Furans; D014316:Tritium; C052546:virginiamycin butanolide C; D014769:Virginiamycin; D011402:Pronase; D015107:4-Butyrolactone