Helicobacter pylori Exploits a Unique Repertoire of Type IV Secretion System Components for Pilus Assembly at the Bacteria-Host Cell Interface
Figure 7
Analysis of pili formed by a ΔcagH mutant strain.
WT H. pylori, a ΔcagH mutant, and a complemented mutant (ΔcagH/CagH-HA) were co-cultured with AGS cells and then analyzed by FESEM. (A) WT strain. (B, C, D) Multiple images of the ΔcagH mutant. (E) High magnification of panel A (WT strain). (F) High magnification of panel B (ΔcagH mutant). (G) ΔcagH/CagH-HA. Magnification bars indicate 200 nm. (H) Use of a position-specific scoring matrix (PSSM) within the NCBI Conserved Domain Database [57] identified a conserved flagellar hook protein K (FlgK) domain in CagH. The alignment compares the region of CagH corresponding to the FlgK domain with sequences of Burkholderia spp. FlgK and sequences of two members of the flagellar hook superfamily that function as molecular rulers (FliK from Salmonella and YscP from Yersinia pestis) [59], [60], [61], [64]. Arrows above the alignment indicate three portions of the FlgK domain identified in CagH.