Open AccessCharacterization of Erwinia chrysanthemi extracellular proteases: cloning and expression of the protease genes in Escherichia coli
Author(s) -
Cécile Wandersman,
Philippe Delepelaire,
Sylvie Létoffé,
Maxime Schwartz
Publication year - 1987
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.169.11.5046-5053.1987
Subject(s) - proteases , biology , escherichia coli , cosmid , protease , microbiology and biotechnology , secretion , molecular cloning , biochemistry , protease inhibitor (pharmacology) , peptide sequence , gene , enzyme , genetics , antiretroviral therapy , viral load , virus
Erwinia chrysanthemi, a phytopathogenic enterobacterium, secretes three antigenically and structurally distinct proteases, A, B, and C and produces a protease inhibitor, a low-molecular-weight, heat-stable protein which remains mostly intracellular and which binds specifically to the A, B, and C proteases. The structural genes for proteases A, B, and C and for the inhibitor are clustered on a ca. 40-kilobase DNA fragment present in cosmid pEW4. Escherichia coli strains harboring pEW4 secrete the three proteases into the medium during the exponential phase of growth, without intracellular accumulation and in the absence of detectable cell lysis. An 8.5-kilobase EcoRI fragment derived from the cosmid encodes proteases B and C and the inhibitor as well as functions involved in the synthesis or secretion (or both) of the proteases. The inhibitor is not required for protease synthesis or secretion.