FIG 1.

The M. xanthus che7 locus and phyletic tree of che7 clusters. (A) The che7 cluster contains six chemosensory genes (cheY7, cheA7, cheW7, mcp7, cheR7, and cheB7) as well as accessory genes cpc7 (HEAT repeat protein) and des7 (fatty acid [FA] desaturase). (B) Shown is a phylogenetic tree based on CheA-CheR-CheB concatenated proteins from cyanobacterial and myxobacterial species that possess Cpc homologs (see the text). Gene order for the corresponding clusters is shown at right. Blue shaded boxes indicate cyanobacterial species containing che7. Orange shaded boxes indicate myxobacteria containing che7. cpc7 is conserved in most che7 clusters, whereas des7 is specific to Myxococcus species.