Clustering of Cas1 into distinct phylogenetic groups.

<p>Cas1 protein sequences were aligned using the MUSCLE algorithm and used to generate a UPMGA tree to show the divergence of different CRISPR-Cas systems. The system type and sub-type is noted on the right. The (*) indicates <i>B</i>. <i>moukalabense</i> which contained an “Undetermined” CRISPR-Cas system.