Highly conserved DNA sequence present in small plasmids from Selenomonas ruminantium

Plasmid pJW1 from Selenomonas ruminantium subsp. lactilytica strain JW13 ha s been cloned in Escherichia coli vector pBluescriptSK(-) and completely se quenced. The plasmid is only 1410 bp with an overall GC content of 42.2%. C omputer analysis of sequence data revealed a single open reading frame (ORF 1, 146 amino acids, MW 16.525.5 Da) encoding a putative replication protein which is similar to the Rep protein of Ruminobacter, amylophilus plasmid p RAO1. ORF1 is followed by a long AT-rich (75%) region and a region abundant in direct and inverted repeats. Comparison of DNA sequences revealed the p resence of a short (<250 bp) DNA segment which is highly conserved between several small S. ruminantium plasmids including pJDB21, (C) 2000 Academic P ress.