Nucleotides Variability of Branched Chain Ketoacid Dehydrogenase E1-α Polypeptide (BCKDHA) Gene on Madura Cattle

Abstract

Madura cattle is one of Indonesian native cattle which has physical strength and highly adaptable under dry climate. Branched Chain α-Keto Dehydrogenase (BCKD) complex that is bound to mitochondrial inner membrane catalyzes branched-chain amino acid catabolism into α-keto. Subunit E1-α of BCKD complex is encoded by Branched Chain Ketoacid Dehydrogenase E1-α Polypeptide (BCKDHA) gene. This research was conducted to analyze variability of 3’ end promoter and exon 1, exon 2 & 3, and exon 8 of BCKDHA gene. Variant analysis was done on 10 samples of madura cattle, 1 sample of filial ongole cattle, and 1 sample of bali cattle. Missense substitution was found in one sample of madura cattle, i.e. G95A that changed polypeptide, i.e. arginine to glutamine (Arg28Glu); other substitution was found in all samples, i.e. T125C and changed polypeptide, i.e. phenylalanine to serine (Phe38Ser). Variant in nucleotide number 19093 of exon 8 caused the changes of Arginine to Cysteine. 
The exon 8 encodes a polypeptide side chain whose function is unknown. Several silent mutations on promoter, exon1, exon 2 and exon 3 were observed in all samples. Apart from the point mutation above, there is a 6 base deletion (ATGGCG) in the exon 1 segment that was identified in four samples of Madura cattle that shortened two amino acids of signal peptide of BCKDHA.