title: Identification and characterization of sawC, a whiA-like gene, essential for sporulation in Streptomyces ansochromogenes.
abstract: sawC, encoding a protein homologous to the WhiA sporulation regulator of Streptomyces coelicolor, was cloned from a fairly distantly related species, Streptomyces ansochromogenes. Disruption of sawC led to formation of aerial mycelium much longer than normal spore chains and with somewhat increased coiling, indicating that sawC plays an important role in the cessation of aerial hyphal growth similar to that of whiA, and that it has an effect on cell wall structure. However, complementation of sawC and whiA mutants with the same DNA fragment gave different results, which suggested that there may be some difference in regulation or function of WhiA/SawC between the two strains. S1 nuclease mapping identified one transcription start point of sawC. Using EGFP as a reporter, the spatial expression of sawC was shown to be confined to aerial hyphae. Computer-aided structural prediction analysis of SawC/WhiA proteins revealed the presence of a fold very similar to the endonuclease domain of PI-PfuI, raising the possibility that these proteins may interact with an intermediate in DNA repair or replication.
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.
authors.forename: Zhoujie
authors.initials: Z
authors.lastname: Xie
authors.forename: Wenli
authors.initials: W
authors.lastname: Li
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Tian
authors.forename: Gang
authors.initials: G
authors.lastname: Liu
authors.forename: Huarong
authors.initials: H
authors.lastname: Tan
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D018360:Crystallography, X-Ray; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D049452:Green Fluorescent Proteins / Q000235:genetics; D025301:Hyphae / Q000502:physiology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017384:Sequence Deletion; D013171:Spores, Bacterial / Q000502:physiology; D013302:Streptomyces / Q000235:genetics / Q000502:physiology*; D024363:Transcription Initiation Site
chemical_list: D001426:Bacterial Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins