MODIFICATIONS OF STREPTOMYCES SIGNAL PEPTIDES AND THEIR EFFECTS ON PROTEIN-PRODUCTION AND SECRETION

As for other organisms, proteins to be secreted in Streptomyces are pr oduced as preproteins consisting of the mature protein preceded by a N -terminal signal peptide which is cleaved off during membrane transloc ation. Although primary sequences are seldom conserved among signal pe ptides, they all have a typical tripartite structure: a basic amino-te rminus, a central apolar core and a carboxy-terminal region containing the signal peptidase recognition site. In vitro mutagenesis studies h ave been carried out on various signal peptides to analyse the structu re-function relationship of each of the three regions of Streptomyces signal peptides. In the current paper the present knowledge of Strepto myces leader sequences and the impact of introduced mutations on trans cription, translation and secretion of homologous and heterologous pro teins is reviewed. (C) 1998 Federation of European Microbiological Soc ieties. Published by Elsevier Science B.V.