Figure 3.

Sequence alignment between VirB6b, VirB6a, and TraD. A, schematic of the overall topology of VirB6 homologs realized according to the consensus prediction of the membrane protein topology program TOPCONS (38). B, CLUSTAL multiple sequence alignment by MUSCLE (3.8), indicating which residues and deletions in VirB6a and TraD correspond to the ones identified with the BTH assay in VirB6b. Sequence similarity is indicated as follows: asterisks, identical (single, fully conserved residue); colons, conserved substitutions (strongly similar properties); periods, semiconserved substitutions (weakly similar properties).