Gene organization and 5'-flanking region sequence of conglutinin: a C-type mammalian lectin containing a collagen-like domain.

Bovine conglutinin is a Ca(2+)-dependent serum lectin specific for N-acetylglucosamine. In the present study, we report the exon-intron organization and the sequence of 5'-regulatory region of the conglutinin gene. The coding region of conglutinin mRNA, which encoded the signal peptide and the sequence of the mature protein of 351 amino acids, consisted of seven exons. Exon III encoded the signal peptide, a cysteine-rich NH2-terminal region and six repeats of a Gly-X-Y triplet with one irregular triplet. The remaining long collagen-like domain (49 Gly-X-Y repeats with one irregular triplet) was encoded by four separate exons (Exon IV-VII). Exon VIII encoded the neck region and Exon IX encoded the carbohydrate-recognition domain. The overall exon-intron organization of conglutinin was very similar to that of mannan (mannose)-binding proteins. However, the presence of 108 bp exons in the gene encoding the collagen-like domain was a characteristic of conglutinin. In the promoter region of the gene, several putative consensus sequences that may be involved in the expression of conglutinin were identified.