New animal lectin structures.

The past year has provided the X-ray crystal structures of both the N-terminal domain of sialoadhesin and the extracytoplasmic domain of the cation-dependent mannose 6-phosphate receptor. These structures represent the first examples from the I- and P-type lectin families and provide important insights into how these transmembrane-spanning receptors function. In addition, structures of galectin-7 and of the carbohydrate-recognition domain of galectin-3 have given evidence of a new galectin quaternary structure. Finally, the structure of tachylectin-2, the first example of a fivefold symmetric beta-propeller protein, sheds light on the role played by this lectin in horseshoe crab host defense.