title: Characterization of a replication locus and formation of a higher-order complex between RepA protein and two inverted repeats in Streptomyces plasmid pSV1.
abstract: We identified the minimal locus of 163-kb plasmid pSV1 of Streptomyces violaceoruber for the replication in S. lividans. This locus comprised a repA gene and an upstream 407-bp sequence containing two inverted repeats (IR-III and IR-IV) within an iteron, an AT-rich region and a 300-bp noncoding sequence (NCS). RepA protein bound specifically to a 94-bp sequence covering the intact IR-III and IR-IV to form multimers of DNA/protein complexes, but was unable to bind specifically to the NCS and the promoter of repA gene. Interestingly, this 'bound' region also leaves eight 1-bp 'unbound' spacers at 7-11-9-11-9-11-9-11-8-bp intervals. RepA protein-protein interaction could form dimers or trimers in vitro. These results suggest that a higher-order complex between pSV1 RepA protein and the long inverted repeats may be formed during the initiation of plasmid replication.
authors.affiliation: Key laboratory of Synthetic Biology, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, the Chinese Academy of Sciences, Shanghai, China.
authors.forename: Yalan
authors.initials: Y
authors.lastname: Chen
authors.forename: Huarong
authors.initials: H
authors.lastname: Tan
authors.forename: Zhongjun
authors.initials: Z
authors.lastname: Qin
mesh_terms: D001483:Base Sequence; D004265:DNA Helicases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004261:DNA Replication; D023061:Gene Order; D056426:Genetic Loci; D055029:Inverted Repeat Sequences; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D055503:Protein Multimerization; D013302:Streptomyces / Q000235:genetics* / Q000378:metabolism*; D015534:Trans-Activators / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D015534:Trans-Activators; C045264:replication initiator protein; D004265:DNA Helicases
keywords: Streptomyces; plasmid; replication