Open AccessExpression of the archaebacterial bacterio-opsin gene with and without signal sequences in Escherichia coli: the expressed proteins are located in the membrane but bind retinal poorly.
Author(s) -
Sadashiva S. Karnik,
Tomoko Doi,
Robert S. Molday,
H G Khorana
Publication year - 1990
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.87.22.8955
Subject(s) - escherichia coli , biology , opsin , membrane protein , gene , bacterial outer membrane , gene expression , signal peptide , microbiology and biotechnology , biochemistry , retinal , membrane , peptide sequence , rhodopsin
In a further effort to obtain functional expression of the bacterio-opsin gene (bop) in Escherichia coli, the bop gene with E. coli signal sequences as well as the bop gene with the native presequence were expressed in E. coli. The location of the expressed products in the E. coli cell and their processing and folding to a structure that binds retinal as in Halobacterium halobium were investigated. All the expressed proteins were in the membrane. The proteins were largely unprocessed, and they were distributed between the outer and the inner membrane. The processed fractions, which were minor, were exclusively in the inner membrane. The processed proteins bound exogenously added all-trans-retinal but only partially, indicating that these proteins were present in at least two folded states.