Cloning and sequencing of the gene Ahy-β encoding a subunit of peanut conarachin

A cDNA expression library of mid-maturation cotyledons of peanut (Arachis hypogaea L. Shanyou 523) was constructed to clone the genes of peanut seed storage proteins. Six clones of cDNA were obtained by immunoscreening with a polyclonal antibody against a 65 kD subunit of conarachin from peanut seeds. The six cDNA clones could be divided into two groups, Ahy-α and Ahy-β. Furthermore, a complete cDNA sequence of Ahy-β was determined by using rapid amplification of cDNA ends (RACE). Northern blot analysis showed that Ahy-β was expressed only in developing peanut embryos. Sequence analysis revealed that the Ahy-β gene with 2507 bp was composed of four exons with 703, 176, 81 and 882 bp and three introns with 71, 72 and 73 bp. The deduced amino acid encoded a protein with 614 residues. Several well characterized elements for promoter were observed in the 342 bp promoter region of Ahy-β and included two TATA-boxes, four CAAT-boxes, a vicilin-box, a G-box, a RY-1 element, two RY-2 elements and a P-element, while a poly-A signal and two additional stop codons existed in the 3′UTR.