C-type lectin-like domains (CTLDs) of higher eukaryotes are protein modules originally identified as carbohydrate-recognition domains (CRDs) in a family of Ca2+-dependent animal lectins.
Less closely related but still definitely homologous CTLDs have been identified in a variety of proteins that do not appear to have carbohydrate-binding activity.
All of the domains in the CTLD group show distinct evidence of sequence similarity and are thus believed to have descended from a common ancestor by a process of divergent evolution.
Secondary structure and disulfide bonding in CTLDs
For further information see:
Drickamer, K and Dodd, RB (1999) C-type lectin-like domains in Caenorhabditis elegans: predictions from the complete genome sequence. Glycobiology, 9, 1357-1369. PDF version.
Dodd, RB and Drickamer, K (2001) Lectin-like proteins in model organisms: implications for evolution of carbohydrate-binding activity. Glycobiology, 11, 71R-79R PDF version.
