Complete nucleotide sequence of a cryptic plasmid from the ruminal bacterium Selenomonas ruminantium HD4 and identification of two predicted open reading frames

a cryptic plasmid (pSR1) isolated from Selenomonas ruminantium HD4 was prev iously cloned into the HindIII site of pBR322 and a restriction map was con structed using HindIII, ClaI, BamHI, and PvuII (S. A. Martin and R. G. Dean , Appl. Environ. Microbiol. 55(12), 3035-3038, 1989). Analysis of the nucle otide sequence of pSR1 revealed two major open reading frames (ORFs) locate d in the minus strand at different frames. Analysis of ORF-1 revealed that it has 325 amino acids with a predicted MW of 36,588, and ORF-2 has 379 ami no acids with a predicted MW of 42,651. The ORF-1 amino acids showed 30 to 32% sequence homology to the hypothetical protein YtqA in Bacillus subtilis and another hypothetical protein in the thermophilic bacterium Aquifex aeo licus. ORF-2 showed limited homology (23%) to the hypothetical protein ICFG in the photosynthetic cyanobacteria Synechocystis PCC6803. (C) 1999 Academ ic Press.