Fig. 2.

Deletion of rv3058c or overexpression of esxS-esxR complements in vitro growth defects of esxG/H mutant strains. (A) Cultures of double mutants (ΔesxGΔrv3058c, ΔesxHΔrv3058c, and Δesx-3Δrv3058c) were plated in parallel onto media containing and lacking 200 ng/mL mycobactin J in comparison with the H37Rv WT strain. Deletion of rv3058c permits growth of ΔesxG and ΔesxH but not Δesx-3. (B) ΔesxH was transformed with pMV361 vector expressing esxGH or esxRS and selected on kanamycin; equivalent inocula were plated on 7H10 medium with and without mycobactin J. Both constructs rescued growth in the absence of mycobactin J. Below is a schematic illustrating the genomic organization of the esxRS locus; the location of the putative Rv3058c binding site upstream of pe29 is indicated. (C) H37Rv WT, ΔesxGH, and Δesx-3 were transformed with pMV361 EV or with pMV361 vector expressing esxGH or esxRS and selected on kanamycin. Equivalent numbers were plated on media with and without mycobactin J. Both the esxGH- and the esxRS-expressing constructs but not the EV rescued growth of ΔesxGH on standard 7H10 lacking mycobactin J. In contrast, growth of Δesx-3 was not rescued by any of the constructs.