STRUCTURAL-ANALYSIS OF A NEW CRYPTIC PLASMID PAR67 ISOLATED FROM RUMINOCOCCUS-ALBUS AR67

The complete nucleotide sequence of a new cryptic plasmid pAR67 isolat ed from a rumen bacterium Ruminococcus albus AR67 has been determined. The plasmid pAR67 was 3419 bp in size with a 45% GC content. Two open reading frames, ORF1 and ORF2, encoding potential polypeptides of 285 and 165 amino acids. with limited sequence similarity to replication and mobilization proteins? respectively, were identified within the se quence. The region upstream of ORF1 had an AT-rich (80%) segment follo wed by four 19-bp direct repeats, which is similar to the structural o rganization characteristic of replication origins of some bacterial pl asmids. (C) 1998 Academic Press.