FIG. 1.

(A) Structure of gene cluster containing omcF (DL1) and mutation scheme for OmcF-deficient strain DLBK01. The omcF gene was replaced with a kanamycin cassette in mutant DLBK01 (omcF::kan). The gene replacement is indicated by a horizontal bar. The transcriptional orientation of the kanamycin resistance cassette (Kan^r) is the same as that of omcF and is indicated by a horizontal arrow. “S” indicates SmaI sites. The current annotation (36) of the genes surrounding omcF is as follows: orfA, ATP-dependent protease; orfC, putative membrane protein; and orfD, SPFH/band 7 domain protein. (B) Confirmation of omcF::kan genotype by Southern blot analysis. Wild-type and OmcF-deficient mutant genomic DNA were cleaved with SmaI, blotted, and probed with a 2.2-kb DNA fragment amplified from the omcF::kan strain with primers 4017-1 and 4017-6 (Table 1). The expected labeled fragments are 0.9 kb and 0.42 kb long for the wild type (WT) and 2.1 kb and 0.39 kb long for the mutant.