AMINOPEPTIDASE FROM STREPTOMYCES-GRISEUS - PRIMARY STRUCTURE AND COMPARISON WITH OTHER ZINC-CONTAINING AMINOPEPTIDASES

The aminopeptidase from Streptomyces griseus is a calcium-activated me talloenzyme, which contains 2 mol tightly bound zinc/mol protein. This aminopeptidase rapidly hydrolyzes peptide bonds formed by N-terminal hydrophobic amino acids, such as leucine, methionine and phenylalanine . We have determined the complete primary structure of the protein, wh ich contains 284 amino acid residues, yielding a molecular mass of 297 23 Da. A search in the Swiss-Prot database for sequence similarities r evealed a low degree of identity (26-34%) to Saccharomyces cerevisiae aminopeptidase Y, Aeromonas proteolytica aminopeptidase, and a hypothe tical 49.5-kDa protein from Bacillus subtilis, which is supposed to be long to the aminopeptidase Y family. In all these proteins, the residu es that are known to be involved in zinc coordination are conserved.