title: AmfS, an extracellular peptidic morphogen in Streptomyces griseus.
abstract: The amf gene cluster was previously identified as a regulator for the onset of aerial-mycelium formation in Streptomyces griseus. The nucleotide sequences of amf and its counterparts in other species revealed a conserved gene organization consisting of five open reading frames. A nonsense mutation in amfS, encoding a 43-amino-acid peptide, caused significant blocking of aerial-mycelium formation and streptomycin production, suggesting its role as a regulatory molecule. Extracellular-complementation tests for the aerial-mycelium-deficient phenotype of the amfS mutant demonstrated that AmfS was secreted by the wild-type strain. A null mutation in amfBA, encoding HlyB-like membrane translocators, abolished the extracellular AmfS activity without affecting the wild-type morphology, which suggests that AmfBA is involved not in production but in export of AmfS. A synthetic C-terminal octapeptide partially induced aerial-mycelium formation in the amfS mutant, which suggests that an AmfS derivative, but not AmfS itself, serves as an extracellular morphogen.
authors.affiliation: Department of Applied Biological Sciences, Nihon University, 1866 Kameino, Fujisawa-shi, Kanagawa 252-8510, Japan. ueda@brs.nihon-u.ac.jp
authors.forename: Kenji
authors.initials: K
authors.lastname: Ueda
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Oinuma
authors.forename: Go
authors.initials: G
authors.lastname: Ikeda
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Hosono
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ohnishi
authors.forename: Sueharu
authors.initials: S
authors.lastname: Horinouchi
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Beppu
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D009154:Mutation; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D013305:Streptomyces griseus / Q000235:genetics* / Q000254:growth & development*
chemical_list: C450432:AmfS protein, Streptomyces griseus; D001426:Bacterial Proteins; D010455:Peptides