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Construction of an overproduction vector containing the novel srp (sterically repressed) promoter
Author(s) -
EzazNikpay Khosro,
Uchino Ken,
Lerner Rachel E.,
Verdine Gregory L.
Publication year - 1994
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1002/pro.5560030117
Subject(s) - overproduction , escherichia coli , biology , microbiology and biotechnology , expression vector , chemistry , biochemistry , gene , recombinant dna
Abstract We report the design, synthesis, and evaluation of a novel Escherichia coli promoter intended for use in overproduction of proteins that are deleterious to the host. In this sterically repressed promoter ( srp ), the lac operator site is positioned between the ‐10 and ‐35 elements, where it can interfere sterically with RNA polymerase and thereby prevent assembly of a poised transcriptional complex. An srp ‐containing phagemid, pKEN1, and a tac ‐containing phagemid, pHN1, which has been widely used in protein overproduction but is often unstable, are compared with respect to levels of uninduced and induced protein expression. The level of uninduced protein synthesis by the srp promoter in vivo is ∼ 50% of that observed with tac , whereas the leveIs of induced protein synthesis with the 2 vectors are approximately equal. A remarkable increase in stability of overproduction and growth was observed when the toxic Ada protein was overproduced in pKEN1, demonstrating the potential utility of this vector in overproducing toxic proteins.