An unspliced cDNA for human dihydrolipoamide succinyltransferase: characterization and mapping of the gene to chromosome 14q24.2-q24.3.

Abnormality of the dihydrolipoamide succinyltransferase gene may be a cause of familial Alzheimer's disease linked to chromosome 14q24.3. However, the locus of the dihydrolipoamide succinyltransferase gene on this chromosome was uncertain. An unspliced cDNA of about 2.3 kb for human dihydrolipoamide succinyltransferase was isolated. This cDNA contained three exons and four introns and the nucleotide sequences at the 5' donor and 3' acceptor sites of all introns conformed to the gt-ag rule. The amino acid sequences of the three exons support our previous observation that human dihydrolipoamide succinyltransferase lacks a sequence motif for an E1 and/or E3 binding site. The unspliced cDNA was mapped only on human chromosome 14q24.2-q24.3 by fluorescent in situ hybridization. Thus the dihydrolipoamide succinyltransferase gene is concluded to be located on human chromosome 14q24.2-q24.3.