Complex sentence: A set of genes were found to be associated with CRISPR repeats (the "cas", or "CRISPR-associated" genes) some of the genes encoded putative nuclease or helicase proteins, which are enzymes that can cut DNA.
Split into simpler sentences: A set of genes were found to be associated with CRISPR repeats (the "cas", or "CRISPR-associated" genes). Com of these genes encoded putative nuclease or helicase proteins, which are enzymes that can cut DNA.