title: The legumin gene family: structure of a B type gene of Vicia faba and a possible legumin gene specific regulatory element.
abstract: The field bean, Vicia faba L. var. minor, possesses two sub-families of 11 S legumin genes named A and B. We isolated from a genomic library a B-type gene (LeB4) and determined its primary DNA sequence. Gene LeB4 codes for a 484 amino acid residue prepropolypeptide, encompassing a signal peptide of 22 amino acid residues, an acidic, very hydrophilic alpha-chain of 281 residues and a basic, somewhat hydrophobic beta-chain of 181 residues. The latter two coding regions are immediately contiguous, but each is interrupted by a short intron. Type A legumin genes from soybean and pea are known to have introns in the same two positions, in addition to an extra intron (within the alpha-coding sequence). Sequence comparisons of legumin genes from these three plants revealed a highly conserved sequence element of at least 28 bp, centered at approximately 100 bp upstream of each cap site. The element is absent from the equivalent position of all non-legumin and other plant and fungal genes examined. We tentatively name this element "legumin box" and suggest that it may have a function in the regulation of legumin gene expression.
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D007887:Fabaceae / Q000235:genetics*; D005796:Genes; D005809:Genes, Regulator; D008040:Genetic Linkage; D010940:Plant Proteins; D014674:Plant Proteins, Dietary / Q000235:genetics*; D010946:Plants, Medicinal; D012333:RNA, Messenger / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic; D000097793:Legumins
chemical_list: D010940:Plant Proteins; D014674:Plant Proteins, Dietary; D012333:RNA, Messenger; D000097793:Legumins