The single-stranded-DNA-binding protein encoded by the Escherichia coli F factor can complement a deletion of the chromosomal ssb gene.
Genes encoding single-stranded-DNA-binding proteins (SSBs) are carried by a variety of large self-transmissible plasmids, and it previously has been shown that these plasmid-borne genes can complement conditional lethal alleles of the ssb gene on the Escherichia coli chromosome for cellular viability. We have tested one of the plasmid-borne ssb genes, the ssf gene from the E. coli F factor, for its ability to complement total deletion of the chromosomal ssb gene for viability. We have found that ssf can complement the ssb deletion, but only when it is present on a high-copy-number plasmid. Cells that are totally dependent on the F-factor-encoded SSB for viability manifest growth properties indicative of problems in DNA replication.
Porter
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RD
Department of Molecular and Cell Biology, Pennsylvania State University, University Park 16802.
Black
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D000595:Amino Acid Sequence; D015139:Blotting, Southern; D002872:Chromosome Deletion; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D005144:F Factor / Q000235:genetics*; D005798:Genes, Bacterial; D005804:Genes, Lethal; D007763:Lac Operon / Q000235:genetics; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid
D004268:DNA-Binding Proteins