Fig. 3

Vector design for Cas9/sgRNA mediated genome editing in M. xanthus. a The Cas9/sgRNA expression plasmids were constructed in vector pSWU30. The cas9 gene was promoted by the constitutive promoter (P_pilA) or the copper-inducible promoter (P_cuoA), and the tRNA–sgRNA–tRNA chimeric gene was transcribed from the T7A1 promoter or the P_pilA promoter and terminated by T7 terminator. b Construction of sgRNA transcription cassette. The model cassette was artificially synthesized and cloned into pUC57. Two primers, general primer gRNA-F and custom primer SgXR, which contained specific 20 nt spacer, were used to produce new target site