THE GENE ENCODING THE BIOTIN-APOPROTEIN LIGASE OF SACCHAROMYCES-CEREVISIAE

We report the isolation, genomic mapping, and DNA sequence of the BPL1 gene encoding the biotin-apoprotein ligase of Saccharomyces cerevisia e. The gene was isolated by complementation of an Escherichia coli bir A (biotin-apoprotein ligase) mutant indicating that the expressed yeas t protein modified the essential biotinated protein of the bacterial h ost. The BPL1 gene encodes a protein of 690 residues (M(r) 76.4 kDa) w ith strong sequence similarites to the E. coli and human biotin-apopro tein ligases. BPL1 was mapped to chromosome IV, is allelic to the prev iously described ACC2 gene, and encodes the major (if not the only) bi otin-apoprotein ligase activity of S. cerevisiae.