Sequence analysis of plasmid pCC5.2 from cyanobacterium Synechocystis PCC 6803 that replicates by a rolling circle mechanism.
The cyanobacterium Synechocystis sp. strain PCC 6803 contains several cryptic plasmids of 2.4, 5.2, and about 50 or 100 kbp. The complete nucleotide sequence of the 5.2-kbp plasmid, pCC5.2, has been analyzed and is reported here. This plasmid contains 5214 bp and 53.1% A+T. Six open reading frames, ORFs A-F (encoding peptides of larger than 90 amino acid residues), were located on both strands of pCC5.2. ORF B codes for a potential replication protein containing 971 amino acids, for which there are three homologous proteins encoded by other cyanobacterial plasmids. ORF C encodes a polypeptide of 93 amino acids which shares homologies with products of two ORFs found in the protein database. Counterparts of the products of ORF A, D, E, and F could not be found in the protein database. Detection of a single-stranded DNA intermediate during replication of pCC5.2 indicates that this plasmid may also replicate by a rolling circle mechanism, as has been reported for pCA2.4 and pCB2.4 from the same strain of Synechocystis (PCC 6803).
Xu
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Department of Biochemistry and Biophysics, Washington State University, Pullman 99164-4660, USA.
McFadden
B A
BA
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D002874:Chromosome Mapping; D000458:Cyanobacteria / Q000235:genetics*; D004261:DNA Replication; D004269:DNA, Bacterial / Q000235:genetics; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010957:Plasmids / Q000235:genetics*; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D004269:DNA, Bacterial