Functional characterization of a type I-F1 CRISPR-Cas system from the clinical isolate Shewanella xiamenensis Sh95
In this study, the genetic context and activity of a type I-F1 CRISPR-Cas system within the species from the clinical isolate Shewanella xiamenensis Sh95 (SxCRISPR-Cas3) was explored. The system was reprogrammed to target plasmid sequences revealing functional activity through plasmid interference and curing. The transcriptional analysis showed constitutive transcription. The genomic context was also explored for which the upstream region of SxCRISPR-Cas3 system sequence was determined by PCR, subsequent Sanger sequencing, and assembly of S. xiamenensis Sh95 contigs 66 (accession number NZ_LGYY01000278.1) and 16 (accession number NZ_LGYY01000138.1). Contig 66 contains Sh95-alpA-1 and a second alpA gene of putative phage origin named Sh95-alpA-2 (for simplicity), whereas the contig 16 harbor the complete SxCRISPR-Cas3 system.