Figure 5. traA allele–specific interactions in extracellular complementation of gliding motility.

Protein transfer was assayed by the ability of nonmotile recipient mutants (ΔcglC Δtgl) to be complemented extracellularly by a nonmotile, nonstimulatable donor that encodes the wild-type CglC and Tgl proteins [7]–[9]. The four engineered donor strains encoded the indicated traA allele replacements. The recipient strains were merodiploid with the indicated traA alleles and the original traA ^DK1622 allele. Strains were mixed at a 1∶1 cell ratio, and micrographs were taken after 1 day. Images with black borders show traA allele combinations that restore motility, which occurs by protein transfer [9]. Strains are listed in Table S1.