Highly conserved DNA sequence present in small plasmids from Selenomonas ruminantium.

Plasmid pJW1 from Selenomonas ruminantium subsp. lactilytica strain JW13 has been cloned in Escherichia coli vector pBluescriptSK(-) and completely sequenced. The plasmid is only 1410 bp with an overall GC content of 42.2%. Computer analysis of sequence data revealed a single open reading frame (ORF1, 146 amino acids, MW 16,525.5 Da) encoding a putative replication protein which is similar to the Rep protein of Ruminobacter amylophilus plasmid pRAO1. 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 presence of a short (<250 bp) DNA segment which is highly conserved between several small S. ruminantium plasmids including pJDB21. Copyright 2000 Academic Press.