Molecular cloning of a cDNA for α-subunit of rat liver electron transfer flavoprotein

Two cDNA clones for the α-subunit of rat liver electron transfer flavoprotein were isolated and their nucleotide sequences were determined. The longer cDNA contained a protein-coding region of 900 nucleotides and 3′-noncoding region of 335 nucleotides. The identity of the clone was confirmed by matching the amino acid sequence predicted from the cDNA with the sequence of one of the lysyl endopeptidase-digested peptides from the purified α-subunit. The molecular weight of the protein calculated from the protein-coding nucleotides was approx. 3,000 daltons smaller than that of the precursor, suggesting that the cDNA was not of full length. The derived amino acid composition fairly agreed with the chemically determined amino acid composition of the purified α-subunit, indicating that the protein-coding region contains most of the mature α-subunit.