title: Gene duplication with displacement and rearrangement: origin of the bacterial replication protein PriB from the single-stranded DNA-binding protein Ssb.
abstract: PriB is a proteobacterial protein that is involved in the pre-primosomal step of DNA replication and, unexpectedly, is encoded with a ribosomal protein operon. Detailed sequence comparisons and analysis of operon organization show that PriB evolved from the single-stranded DNA-binding (Ssb) via gene duplication with subsequent rapid sequence diversification. Duplication of the SSB gene was accompanied by a genome rearrangement which resulted in one of the paralogs retaining the original position, whereas the other was relocated. The functional specialization of the resulting paralogs apparently proceeded in an unexpected fashion: the original Ssb function remained with the relocated paralog, whereas the one within the ribosomal protein operon acquired a new, specialized function in replication.
authors.affiliation: National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Md., USA.
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Ponomarev
authors.forename: Kira S
authors.initials: KS
authors.lastname: Makarova
authors.forename: L
authors.initials: L
authors.lastname: Aravind
authors.forename: Eugene V
authors.initials: EV
authors.lastname: Koonin
mesh_terms: D000595:Amino Acid Sequence; D004261:DNA Replication / Q000235:genetics; D004269:DNA, Bacterial / Q000502:physiology; D004268:DNA-Binding Proteins / Q000235:genetics*; D029968:Escherichia coli Proteins; D020440:Gene Duplication; D015321:Gene Rearrangement; D008969:Molecular Sequence Data; D009876:Operon; D020560:Proteobacteria / Q000235:genetics*; D016415:Sequence Alignment; D016335:Zinc Fingers / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C086004:PriB protein, E coli