Recombinant bacterial strains with the genes of proteins of interest cloned in plasmids provide an oversynthesis of these proteins, which is important for their large-scale production. However, the enhanced synthesis of protein is accompanied by changes in its biogenesis and accumulation of intermediate forms corresponding to different steps of protein posttranslational modification, as well as by a change in its localization. This review surveys the peculiarities of biogenesis and localization of secreted proteins produced by recombinant strains by the example of Escherichia coli alkaline phosphatase (PhoA). They might be interesting for researchers studying the fundamental and applied aspects of protein oversynthesis by recombinant E coli strains. (C) 2004 Elsevier Ltd. All rights reserved.