Modular architecture of the conjugative plasmid pSVH1 from Streptomyces venezuelae

• Published in: Plasmid Vol. 55; no. 3; pp. 201 - 209
• Main Authors: Reuther, Jens, Wohlleben, Wolfgang, Muth, Günther
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-05-2006
• Subjects: Base Sequence; Conjugation; Conjugation, Genetic - genetics; DNA Replication; Gene Expression Regulation, Bacterial; Molecular Sequence Data; Plasmid; Plasmid transfer; Plasmids; Replicon; Rolling-circle-replication; Sequence Deletion; Sequence Homology, Nucleic Acid; Streptomyces; Streptomyces - genetics; Streptomyces natalensis; Streptomyces venezuelae; Plasmid; Streptomyces; Rolling-circle-replication; Plasmid transfer; Conjugation
• ISSN: 0147-619X; 1095-9890
• DOI: 10.1016/j.plasmid.2005.11.007

The conjugative rolling circle replication (RCR) type plasmid pSVH1 from the chloramphenicol producer
Streptomyces venezuelae was characterized by DNA sequence analysis and insertion/deletion analysis. Nucleotide sequence of the 12,652
bp pSVH1 revealed 11 open reading frames with high coding probability for which putative functions could be assigned. Beside the replication initiator gene
rep for RCR, pSVH1 contained only genes involved in conjugative transfer. The transfer gene
traB encoding the septal DNA translocator TraB is regulated by the GntR-type transcriptional regulator TraR. Six
spd genes involved in intra-mycelial plasmid spreading are organized in two operons, consisting of two and three translationally coupled genes. Subcloning experiments demonstrated that the transfer gene
traB represents a kill function and localized the pSVH1 minimal replicon consisting of
rep and the
dso origin to a 2072-bp fragment. Plasmid pSVH1 showed a modular architecture. Its replication region resembled that of the
Streptomyces natalensis plasmid pSNA1, while the transfer and spread regions involved in conjugative plasmid transfer were highly similar to the corresponding regions of the
Streptomyces ghanaensis plasmid pSG5.