Figure 1.

The Csx27 protein family and associated genes. (A). The FastTree phylogenetic tree of Csx27 homologs overlaid with the pattern of occurrence of the three genes (ComEC-MBL domain, UbP and WYL-HTH) most frequently identified in the loci that encode Csx27 family proteins. The green branch includes the bona fide Csx27 from the subtype VI-b1 CRISPR-Cas systems, and the yellow branch corresponds to the proteins associated with AAA ATPase and adenosine deaminase. Red protein accessions specify proteins that were used to illustrate membrane topology prediction (B) and conserved neighborhood architectures (C). (B). TMHMM prediction for selected proteins. Plot show probability and location of TM helices along the protein. (C). Typical conserved neighborhoods. Genes are shown by directed arrows. Homologous genes are color coded according to the legend shown on the right. (D). Domain organization of ComEC and ubiquitin domain containing protein.