Figure 1.

Domain structure of L27-containing proteins and sequence alignment of L27 domains. (A) The L27 domain is present in multidomain proteins such as the MAGUK proteins that contain additional protein–protein interaction modules such as the PDZ, SH3, and GK domains. (B) Structure-based sequence alignment of L27 domains. Residues involved in hydrophobic packing interactions are in a green background; other residues packing inside are in cyan; additionally conserved or highly similar residues are in magenta. Residues packing within the heterodimer interface are denoted by • (or ▾ for residues that were mutated). Residues packing in the interface between two heterodimers are labeled by □, while those residues packing into both interfaces by ^*.