Proteins with an Euonymus lectin-like domain are ubiquitous in Embryophyta.
BACKGROUND
Cloning of the Euonymus lectin led to the discovery of a novel domain that also occurs in some stress-induced plant proteins. The distribution and the diversity of proteins with an Euonymus lectin (EUL) domain were investigated using detailed analysis of sequences in publicly accessible genome and transcriptome databases.


RESULTS
Comprehensive in silico analyses indicate that the recently identified Euonymus europaeus lectin domain represents a conserved structural unit of a novel family of putative carbohydrate-binding proteins, which will further be referred to as the Euonymus lectin (EUL) family. The EUL domain is widespread among plants. Analysis of retrieved sequences revealed that some sequences consist of a single EUL domain linked to an unrelated N-terminal domain whereas others comprise two in tandem arrayed EUL domains. A new classification system for these lectins is proposed based on the overall domain architecture. Evolutionary relationships among the sequences with EUL domains are discussed.


CONCLUSIONS
The identification of the EUL family provides the first evidence for the occurrence in terrestrial plants of a highly conserved plant specific domain. The widespread distribution of the EUL domain strikingly contrasts the more limited or even narrow distribution of most other lectin domains found in plants. The apparent omnipresence of the EUL domain is indicative for a universal role of this lectin domain in plants. Although there is unambiguous evidence that several EUL domains possess carbohydrate-binding activity further research is required to corroborate the carbohydrate-binding properties of different members of the EUL family.
Fouquaert
Elke
E
Laboratory of Biochemistry and Glycobiology, Department of Molecular Biotechnology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium.
Peumans
Willy J
WJ
Vandekerckhove
Tom Tm
TT
Ongenaert
Maté
M
Van Damme
Els Jm
EJ
D023181:Antimicrobial Cationic Peptides / Q000235:genetics / Q000378:metabolism*; D019295:Computational Biology; D019143:Evolution, Molecular; D020869:Gene Expression Profiling; D010802:Phylogeny; D037121:Plant Lectins / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D010944:Plants / Q000235:genetics* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D020539:Sequence Analysis, Protein
D023181:Antimicrobial Cationic Peptides; C047161:Evonymous europa lectin; D037121:Plant Lectins; D010940:Plant Proteins