title: Identification of the replication region of Streptococcus thermophilus No. 29 plasmid pST1.
abstract: The replication region of the 2.77-kilobases (kb) plasmid pST1 from Streptococcus thermophilus No. 29 was identified. Deletion derivatives of pST1 were introduced into plasmid-free S. thermophilus No. 29 and examined for their ability to replicate autonomously. The nucleotide sequence had one open reading frame encoded for a 315 amino acid protein (Rep). Comparisons with proteins encoded by other Gram-positive bacterial plasmids strongly suggest that the deduced protein (RepS) encoded by pST1 has a replicative role. pST1 also contains a DNA sequence similar to the origin nick sequences of pLP1 or pLAB1000, which initiate plasmid replication at the plus origin. In a maxicell system, E. coli CSR603 carrying pSTUC4 produced a protein that was considered to correspond to the product of the RepS gene. These results strongly suggest that pST1 is replicated following a rolling-circle mechanism via single-stranded DNA intermediates.
authors.affiliation: Technical Research Institute, Snow Brand Milk Products Co., Ltd., Saitama, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Hashiba
authors.forename: R
authors.initials: R
authors.lastname: Takiguchi
authors.forename: K
authors.initials: K
authors.lastname: Joho
authors.forename: K
authors.initials: K
authors.lastname: Aoyama
authors.forename: T
authors.initials: T
authors.lastname: Hirota
mesh_terms: D000595:Amino Acid Sequence; D001345:Autoradiography; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D004261:DNA Replication; D004269:DNA, Bacterial / Q000096:biosynthesis; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D010957:Plasmids; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid; D013291:Streptococcus / Q000737:chemistry / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; C084785:repS protein, Streptococcus thermophilus