Fig. 4
The K333 and E397 residues were required for the regulation of PilBLe0708 in the formation of twitching motility in L. enzymogenes OH11. a Multiple sequence alignment of the PilBLe0708-like proteins. PilB proteins acted as ATPase to supply energy via ATP hydrolysis to promote the extension of type IV pilus (T4P). PilBLe0708, PilBPA4526, PilBXac3239, Lca55_4006, Lgu3211_3877, Lde18482_558, Lar79_1239, Lco07_419, indicated these PilB proteins from Lysobacter enzymogenes OH11, Pseudomonas aeruginosa PA01, Xanthomonas citri, L. capsisi 55, L. gumosus 3.2.11, L. defluvii DSM18482, L. arseniciresistens ZS79, and L. concretionis Ko07, respectively. PilTLe3094 served as the PilT protein from L. enzymogenes OH11, which functioned as ATPase to supply energy via ATP hydrolysis to elicit the retraction of T4P. “Walker A” and “Walker B” are two known motifs that are essential for the ATPase activity of the PilB or PilT family proteins. The conserved P208, Y209, K333 and E397 residues are indicated by green, orange, red and blue triangles, respectively. b Involvement of the K333 and E397 residues in the regulation of PilBLe0708 in twitching formation. Mutation of PilBLe0708 in wild-type OH11 fully impaired twitching motility, while complementation of the plasmid-borne pilBLe0708 rescued this defect. At the wild-type background of strain OH11, chromosomal replacement of K333 to A333 (K333A) or E397 to A397 (E397A), but not P208-A208 (P208A) and Y209-A209 (Y209A) abolished the strain in producing twitching cells