MOLECULAR-CLONING OF THE MURINE BRANCHED-CHAIN ALPHA-KETOACID DEHYDROGENASE E2 SUBUNIT - PRESENCE OF 3'-B1 REPEAT ELEMENTS

The cDNA sequence encoding the murine E2 subunit (dihydrolipoyl transa cylase) of the branched-chain alpha-ketoacid dehydrogenase (BCKAD) com plex was determined. In the region encoding the mature E2 subunit prot ein, both the nucleotide composition and predicted amino acid sequence are highly conserved between murine, human, and bovine species. In co ntrast, the 5' sequence encoding the amino-terminal preprotein sequenc e and 3' untranslated region are less well conserved. The 3'-noncoding region contains sequences highly homologous to the rodent B1 repeat e lements, which are related to human Alu repeat sequences. This finding is similar to the presence of three Alu repeat sequences in the 3'-no ncoding region of human E2 cDNA.