Figure 2. The CRISPR/cas-containing locus in P. acnes. The 16 kb genomic region is present in most type II strains (such as in strain J139), inserted between hutH (encoding a histidine ammonia-lyase) and sir2 (encoding a Sir2 family protein). A few type II strains (e.g., HL050PA2) are CRISPR/cas locus-negative. Type III and type I strains possess fragments of this genomic island-like region inserted between hutH and sir2, indicative of deletion events (marked by the double-headed arrow).