FIG. 1.

Comparative organization of different prsA-like genes. Arrows represent the open reading frames. Arrows with a common color or motif encode homologous products in the different genomes. Those discussed in the text are the following: plp (prsA-like protein), pepF (peptidase F), CAM (similar to a caffeoyl-CoA O-methyltransferase), alaRS (alanyl-tRNA synthetase), HIT (histidine triad proteins), speB (exotoxin SpeB), tpt (fibrial tuft organization from S. cristatus), plasmid-borne prtP (cell wall protease) and prtM (PtrP maturase), cbf1 and yhaM (similar to CMP-binding factor), spoVT (stage V sporulation protein T from B. subtilis), and mfd (transcription repair coupling factor mfd from B. subtilis). The double arrows indicate the conserved promoter region of plp2 and plp4 from C. acetobutylicum and C. difficile, respectively.