Open AccessCharacterization of the 12S globulin complex of Brassica napus
Author(s) -
SJÖDAHL Staffan,
RÖDIN Joakim,
RASK Lars
Publication year - 1991
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1991.tb15857.x
Subject(s) - brassica , complementary dna , biology , amino acid , protein subunit , gene , cdna library , arabidopsis , peptide sequence , globulin , biochemistry , genetics , botany , mutant , immunology
Cruciferin (125 globulin) is the major seed protein in Brassica napus (oil seed rape). It is synthesized during seed development and consists of six subunit pairs. Each of these pairs is synthesized as a precursor containing one α and one β chain. Atleast three different precursors exist (P1–3), giving rise to four different mature subunits (cru1–4). Several cruciferin clones were isolated from a seed mRNA cDNA library. Comparison of the deduced amino acid sequences of these clones to amino acid sequences of purified cruciferin chains and peptides identified them as coding for cru2/3 and cru4 subunits. From the amino acid sequences deduced from two overlapping cDNA clones, the precursor of the cru4 subunit was shown to consist of 465 amino acid residues. Comparison of cruciferin and cruciferin‐related sequences from B. napus and Arabidopsis thaliana , respectively, suggested that early during evolution the Brassicaceae family only possessed two types of 11–12S globulin genes, like the present‐day Fabaceae .