Nucleotide sequence of a cDNA for the dihydrolipoamide acetyltransferase component of human pyruvate dehydrogenase complex.

Deoxynucleotide sequencing of a cDNA for the dihydrolipoamide acetyltransferase (PDC-E2) component of human pyruvate dehydrogenase complex (PDC) revealed an open reading frame of 1848 base pairs corresponding to a leader sequence of 54 amino acids and a mature protein of 561 amino acids (59,551 Da). Both an amino-terminal lipoyl-bearing domain and a carboxy-terminal catalytic domain are present in the deduced amino acid sequence. The lipoyl-bearing domain contains two repeating units of 127 amino acids, each harboring one lipoic acid-binding lysine. Thus, mammalian PDC-E2 differs as to the number of lipoic acid-binding sites from other dihydrolipoamide acyltransferases in both prokaryotic and eukaryotic organisms.