Conclusion
ATCC 29803 possesses genomic components required to express the type II-A CRISPR/Cas system, which potentially functions as an RNA-guided endonuclease.
Methods
We performed polymerase chain reaction-amplicon sequencing and de novo genome sequencing to evaluate the presence of the CRISPR/Cas system in four strains.
Results
Only ATCC 29803 possessed cas1, cas2, cas9, and csn2 genes, a CRISPR array, and tracrRNA. The sequences of most components were identical between the CRISPR/Cas systems of ATCC 29803 and ATCC 23064, whereas the spacer sequences and a region of the cas9 gene were different. Unlike the CRISPR/Cas system of ATCC 23064, the cas9 gene of ATCC 29803 was not disrupted by the presence of stop codons.