FIG 2.

Topology and comparison of ComZ domains with structurally related proteins. (A) Topology of ComZ and related folds. (Upper) Topology diagram of ComZ, with the pilin-like domain in purple and the β-solenoid domain in orange. (Lower) Folds of the related proteins GspK and FfIBP are aligned below their mapped superpositions to the equivalent ComZ domains. (B) Superpositions of related structural folds with their equivalent domains from ComZ. (Left) GspK from E. coli (PDB entry 3CIO; pilin domain only) is shown in yellow, and the ComZ pilin-like domain is in purple. (Right) The ice-binding protein FfIBP (4NU2) from Flavobacterium frigoris is in dark blue, and the β-solenoid domain is in orange. Superpositions were carried out using SSM matching, as implemented in CCP4MG (72); root mean square deviation values were 3.25 Å (GspK) and 2.33 Å (FfIBP). Colors are the same as those for panel A.