Isolation and sequence analysis of the rat dihydrolipoamide succinyltransferase gene

The dihydrolipoamide succinyltransferase (DLST) gene of the alpha-ketoglutarate dehydrogenase complex (alpha-KGDC) was isolated from a rat genomic DNA library and sequenced. This gene was composed of 15 exons and 14 introns like the human DLST gene. Sequence analysis of the promoter-regulatory region of the rat DLST gene-(Dlst) showed the possible presence of a CAAT box-sequence and of the sequences for an AP-2 site and three Sp1 sites, but no TATA box-sequence was evidenced. The nucleotide sequences of introns 1 and 4 of the rat Dlst were significantly homologous to those of introns 1 and 4 of the human DLST gene. The sequence analysis of the rat Dlst suggested that the exon coding for the E3- and/or E1-binding domain may have been lost from the gene during evolution in eukaryotic DLST, possibly after mitochondrial symbiosis because prokaryotic DLST possesses the E3- and/or E1-binding domain.