Journal of Biological Chemistry
Volume 270, Issue 42, 20 October 1995, Pages 24858-24863
Journal home page for Journal of Biological Chemistry

Nucleic Acids, Protein Synthesis, and Molecular Genetics
The Role of the Leader Sequence Coding Region in Expression and Assembly of Bacteriorhodopsin (∗)

https://doi.org/10.1074/jbc.270.42.24858Get rights and content
Under a Creative Commons license
open access

Bacterio-opsin is made as a precursor in Halobacterium halobium, which has 13 additional residues at the amino terminus. The codons for these residues have been proposed to form a hairpin structure in the mRNA and play a role in ribosome binding; the leader peptide sequence also has been proposed to have a role in membrane insertion of bacteriorhodopsin (BR). We have made mutations in the bop gene region coding for the leader sequence and expressed the mutant genes in an H. halobium mutant lacking wild-type BR. The leader sequence coding region was found to be important for the stability of the mRNA and for its efficient translation. Single base substitutions in this region that did not affect the amino acid sequence caused significant reductions in protein expression. Deletion of the leader region resulted in unstable mRNA and almost no BR production. Introduction of a new ribosome-binding sequence within the coding region of the mature protein restored mRNA stability and some protein expression. Protein made without the leader peptide was properly assembled in the membrane.

Cited by (0)

This work was supported in part by Grant GM38142 from the National Institutes of Health (to M. T.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

§

Present address: R. W. Johnson Pharmaceutical Research Inst., Raritan, NJ 08869.

Present address: McLaughlin Research Inst. for Biomedical Sciences, Great Falls, MT 59405.