Characteristics of the three CRISPR (1, 2, 3) arrays present in Synechocystis 6803.

For each CRISPR, the repeat sequence and single occurring mutant variants near the 3′ end are given in brackets (the widely conserved [8] 3′ end GAAAC is underlined, and the mutated nucleotide is in boldface). The position of the TSS in the plasmid pSYSA defines the 5′ leader as the region between it and the first repeat. The number of spacers and the range of their lengths are given in addition to spacer-repeat unit duplications. Consecutive identical spacer-repeat units are separated by a dash, whereas duplicated unit pairs are united by a slash.