DNA library screening and scheme of carocin S2 gene. (A) The TF1-2 probe was used to screen DNA fragments from the genomic DNA library of F-rif-18. The DNA was digested with various restriction enzymes as follows: 1. Hpy188I; 2. HindIII; 3 HpaI; 4. EcoRV; 5. EcoRI; 6. ClaI; 7. BsaAI; 8. BglII; 9. BamHI; 10. AhdI; M. DNA leader marker; C. The TF1-2 probe DNA. The arrowhead indicates the 5.7-kb carocin S2 fragment. (B) Shown is the 5.7-kb segment of DNA containing the carocin S2. The location of TF1-2 probe and part amplicon of cDNA of caroS2K and caroS2I were shown.