Characterization of a plasmid replicative origin from an extreme thermophile.
The minimal replicative origin from a 16-kbp natural plasmid of Thermus sp. ATCC 27737 is described. The 1798-bp sequence encodes a single protein (RepA) whose expression is required for replication. This requirement is extended to 200 bp upstream the coding region, which contains promoter-like sequences transcriptionally active in E. coli. Despite the absence of typical iterons, we show that an N-terminal fragment of this protein binds to a DNA fragment internal to its own coding sequence. As this DNA fragment contains an unusually A + T rich sequence surrounded by C + G rich stretches, the possible location of the replicative origin within the region encoding RepA is proposed.
Centro de Biología Molecular Severo Ochoa, UAM-CSIC, Universidad Autónoma de Madrid, Spain.
M
M
de Grado
I
I
Lasa
J
J
Berenguer
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000032:analysis; D018741:Replication Origin / Q000235:genetics*; D015183:Restriction Mapping; D013824:Thermus / Q000235:genetics* / Q000254:growth & development; D014169:Transformation, Bacterial
D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins; C114293:RepA protein, Thermus