FIG 1.
PilN, PilO, PilP, and Tgl are required for T4P-dependent motility in M. xanthus. (A) Model of the T4P machinery. The color code for the proteins is similar to the one used for the genes in the genetic map. PilD is not included in the model of the machinery. Genes and proteins are not drawn to scale. OM, outer membrane; IM, inner membrane. All the pil genes are clustered at the same locus, but not all pil genes are shown (49). tgl is not part of the pil cluster. (B) Motility phenotypes of the indicated mutants and complementation strains. Strains in the same column all contain the same in-frame deletion. Strains were incubated at 32°C for 24 h on 0.5% agar–0.5% CTT. Scale bar, 1 mm. (C) Immunoblots of T4PS protein accumulation. Total cell lysates from exponentially growing cultures were separated by SDS-PAGE (proteins from 7 × 107 cells loaded per lane) and analyzed by immunoblotting using specific antibodies as indicated. For PilQ, only the heat- and detergent-resistant oligomer is shown. The middle lane in each blot contains lysate from the relevant in-frame deletion mutant, and the last lane contains lysate from the relevant complementation strain.