THE (QXW)(3) DOMAIN - A FLEXIBLE LECTIN SCAFFOLD

Lectins form a class of proteins that have evolved a specialized carbo hydrate-binding function. Based on amino acid sequence analysis, sever al lectin families have been described and a lectin domain, the (QxW)( 3) domain, was discussed recently based on 11 family members. In this paper, the (QxW)(3) domain family is extended to 45 sequences, several of which have very low sequence identity with the previously known me mbers of the family. A hidden Markov model was used to identify the mo st divergent members of the family. The expanded set of sequences give s us a more complete appreciation of the conserved features, and the l ack thereof, in this lectin family. This, in turn, provides new insigh ts in the structural and functional properties of the individual famil y members.