Wild-type and mutant bacterioopsins D85N, D96N, and R82Q: high-level expression in Escherichia coli.
The integral membrane protein bacterioopsin, found in the extremely halophilic archaebacterium Halobacterium halobium, was expressed in Escherichia coli as a fusion protein containing 13 heterologous amino acids at the amino terminus. The expressed protein was localized primarily to the E. coli cytoplasmic membrane (greater than 80%) and had an in vivo half-life of 26 min. The amount of bacterioopsin in E. coli crude lysates was quantitated immunologically from Western blots and was expressed at 10-20-fold higher levels than seen previously (i.e., 17 mg/L; 5.6% of the total protein). Three distinct forms of the protein were detected immunologically: two of the forms were generated by the removal of either one or four amino acid residues at the amino terminus; the third form remained unaltered.
Shand
R F
RF
Department of Biochemistry and Biophysics, University of California, San Francisco 94143-0448.
Miercke
L J
LJ
Mitra
A K
AK
Fong
S K
SK
Stroud
R M
RM
Betlach
M C
MC
D000595:Amino Acid Sequence; D001345:Autoradiography; D001436:Bacteriorhodopsins / Q000235:genetics*; D001483:Base Sequence; D015153:Blotting, Western; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005822:Genetic Vectors; D006207:Half-Life; D006217:Halobacterium / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation
D001436:Bacteriorhodopsins; C017827:bacterio-opsin