A novel family of lectins evolutionarily related to class V chitinases: an example of neofunctionalization in legumes.
A lectin has been identified in black locust (Robinia pseudoacacia) bark that shares approximately 50% sequence identity with plant class V chitinases but is essentially devoid of chitinase activity. Specificity studies indicated that the black locust chitinase-related agglutinin (RobpsCRA) preferentially binds to high-mannose N-glycans comprising the proximal pentasaccharide core structure. Closely related orthologs of RobpsCRA could be identified in the legumes Glycine max, Medicago truncatula, and Lotus japonicus but in no other plant species, suggesting that this novel lectin family most probably evolved in an ancient legume species or possibly an earlier ancestor. This identification of RobpsCRA not only illustrates neofunctionalization in plants, but also provides firm evidence that plants are capable of developing a sugar-binding domain from an existing structural scaffold with a different activity and accordingly sheds new light on the molecular evolution of plant lectins.
Van Damme
Els J M
EJ
Department of Molecular Biotechnology, Laboratory of Biochemistry and Glycobiology, Ghent University, 9000 Gent, Belgium. elsjm.vandamme@ugent.be
Culerrier
Raphaël
R
Barre
Annick
A
Alvarez
Richard
R
Rougé
Pierre
P
Peumans
Willy J
WJ
D000595:Amino Acid Sequence; D005075:Biological Evolution; D050260:Carbohydrate Metabolism; D002688:Chitinases / Q000737:chemistry / Q000378:metabolism*; D003001:Cloning, Molecular; D008958:Models, Molecular; D008969:Molecular Sequence Data; D005810:Multigene Family; D024301:Plant Bark / Q000737:chemistry / Q000378:metabolism*; D037121:Plant Lectins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D031301:Robinia / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014026:Nicotiana / Q000737:chemistry / Q000201:enzymology
D037121:Plant Lectins; D002688:Chitinases