Structural and Functional Studies on the Interaction of GspC and GspD in the Type II Secretion System
(A) Structural superposition of the ETEC GspCHR domain with the N. meningitidis PilP structure (PDB 2IVW) . GspC and NmPilP are colored in green and yellow, respectively. Flexible N- and C-terminal residues of NmPilP are not shown for clarity. The conserved hydrophobic residues are shown as sticks. (B) Surface representation of GspC and PilP in the same orientation as in (A). The crevice on the surface of PilP is absent in GspC. (C) Sequence alignment of GspC and NmPilP based on the structural superposition in (A). Secondary structure elements of GspC and NmPilP are displayed above and below the sequences, respectively; the colored dots represent the conserved hydrophobic residues of GspC and NmPilP.