S-type lectins occur also in invertebrates: high conservation of the carbohydrate recognition domain in the lectin genes from the marine sponge Geodia cydonium.
The marine sponge Geodia cydonium contains several lectins. The main component, called lectin-1, is composed of three to four identical subunits. The subunits of the lectins were cloned from a cDNA library; two clones were obtained. From the deduced aa sequence of one clone, LECT-1, a mol. wt of 15,313 Da is calculated; this value is in good agreement with mass spectrometric analysis of 15,453 +/- 25 Da. The sequence of another clone, LECT-2, was analysed and the aa sequence was deduced (15,433 Da). The two subunits have a framework sequence of 38 conserved aa which are characteristic for the carbohydrate-binding site of vertebrate S-type lectins. Clustering of lectin sequences of various species following their pairwise comparison establishes a dendrogram, which reveals that the sponge lectin could be considered as the ancestor for vertebrate S-type lectins.
Pfeifer
K
K
Institut für Physiologische Chemie, Universität, Mainz, FRG.
Haasemann
M
M
Gamulin
V
V
Bretting
H
H
Fahrenholz
F
F
Müller
W E
WE
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D037161:Galectins; D037102:Lectins / Q000737:chemistry / Q000235:genetics*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D011161:Porifera / Q000737:chemistry*
D037161:Galectins; D037102:Lectins; C081157:lectin-1, Geodia cydonium; D004247:DNA