Site-directed mutagenesis of La protease. A catalytically active serine residue
Comparative sequence analysis of Escherichia coli ATP-dependent La protease led to the suggestion that Ser679is the catalytically active enzyme residue. Site-directed mutagenesis Ser679→ Ala, investigation of the cells containing the mutant plasmid, and study of the partially purified mutant protein produced results in favour of this suggestion. © 1991.