AMINO-TERMINAL BLOCKING GROUP AND SEQUENCE OF THE ANIMAL FATTY-ACID SYNTHASE

We have cloned and sequenced the cDNA encoding the chicken fatty acid synthase. Based on the nucleotide-derived amino acid sequence of the c hicken synthase, the N-terminal sequences are highly conserved among a nimal species, suggesting that translation of the animal synthases ini tiates with the same ATG codon. Like other fatty acid synthases, the N H2-terminal sequence of the chicken enzyme is blocked. We have isolate d and purified the blocked NH2-terminal peptide from a tryptic digest of chicken synthase and have established that the blocking group is an acetyl group. The sequence of the native tryptic peptide confirmed th e cDNA-derived amino acid sequence and suggested that all animal synth ases begin with this homologous sequence. We developed simple procedur es that can be used to isolate and characterize any blocked NH2-termin al peptide. (C) 1994 Academic Press, Inc.