Cloning, Identification and Analysis of Biochemical Characteristics as well as the Phylogeneticism of a Thioredoxin H Gene from Grape (Vitis Vinifera L. Cv. Bidaneh Sefid)

Thioredoxins (Trxs) are small heat-stable proteins that are involved in the cell redox regulation and are present in all organisms from prokaryotes to higher eukaryotes. In higher plants, Trxs can be classified into six different groups namely: the chloroplastic Trxs f, m, x, and y, the mitochondrial Trx o and the Trxs h. The Trxs h are represented by a small multigenic family that participate in such multiple processes as cellular protection against oxidative stress. A full-length cDNA coding for a thioredoxin h (VvTrxh3) gene was cloned from grape (Vitis vinifera L. cv. Bidaneh Sefid) leaf tissue through Reverse Transcription Polymerase Chain Reaction (RT-PCR) technique, and then, biochemical, structural and phylogenetic characteristics were analyzed. Nucleotide sequence analysis revealed an open reading frame of cloned VvTrxh3 gene with a length of 345bp, encoding a protein of 114 amino acid residues. Protein sequence analysis revealed that this gene with thioredoxin fold, contains a typical catalytic site of WCGPC, the calculated molecular mass, and the predicted isoelectric point of the deduced polypeptide of 12.79 kDa and 5.06, respectively. Phylogenetic and multiple alignment studies revealed that this gene is a thioredoxin h belonging to the subclass IA from subgroup I, with a high degree of similarity with plant thioredoxins h