FIGURE 1.

Monomer of MBL. A, schematic representation of the MBL polypeptide. Each polypeptide chain in rat MBL contains 221 residues and is composed of an N-terminal cysteine-rich region, a collagenous region with 19 Gly-Xaa-Yaa triplet repeats, an α-helical neck region, and a C-terminal carbohydrate recognition domain. B, MBL monomer is composed of three identical polypeptide chains. Potential sites of flexibility in the monomer include the swivel region, located between the collagenous and neck regions, the kink region where there is an interruption in the triplet repeats of the collagenous region, and the hub region between the N-terminal cysteine-rich region and the collagenous region.