Abstract
The 42-1 lamB-lacZ gene fusion confers a conditionally lethal, export-dependent phenotype known as maltose sensitivity. A maltose-resistant mutant showing decreased beta-galactosidase activity of the hybrid protein, designated prlF1 (protein localization), was unlinked to the lamB-lacZ fusion. This mutation mapped at 70 min on the Escherichia coli linkage map and conferred maltose resistance, a 30-fold reduction in beta-galactosidase activity, and a 30% decrease in cellular growth rate at 30 degrees C that was independent of the presence of a gene fusion. prlF1 also decreased the beta-galactosidase activity and relieved the maltose sensitivity conferred by fusions of lacZ to the gene specifying the periplasmic maltose-binding protein, malE. The decrease in beta-galactosidase activity, however, was specific for exported hybrid proteins. When export of the hybrid protein was blocked by a signal sequence mutation, prlF1 decreased the beta-galactosidase activity only 2.5-fold. Similarly, prlF1 did not affect the beta-galactosidase activity of fusions of lacZ to a gene specifying a nonexported protein, malK.
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- Bassford P. J., Jr, Silhavy T. J., Beckwith J. R. Use of gene fusion to study secretion of maltose-binding protein into Escherichia coli periplasm. J Bacteriol. 1979 Jul;139(1):19–31. doi: 10.1128/jb.139.1.19-31.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Benson S. A., Silhavy T. J. Information within the mature LamB protein necessary for localization to the outer membrane of E coli K12. Cell. 1983 Apr;32(4):1325–1335. doi: 10.1016/0092-8674(83)90313-6. [DOI] [PubMed] [Google Scholar]
- Casadaban M. J. Transposition and fusion of the lac genes to selected promoters in Escherichia coli using bacteriophage lambda and Mu. J Mol Biol. 1976 Jul 5;104(3):541–555. doi: 10.1016/0022-2836(76)90119-4. [DOI] [PubMed] [Google Scholar]
- Chamberlain J. P. Fluorographic detection of radioactivity in polyacrylamide gels with the water-soluble fluor, sodium salicylate. Anal Biochem. 1979 Sep 15;98(1):132–135. doi: 10.1016/0003-2697(79)90716-4. [DOI] [PubMed] [Google Scholar]
- Emr S. D., Hall M. N., Silhavy T. J. A mechanism of protein localization: the signal hypothesis and bacteria. J Cell Biol. 1980 Sep;86(3):701–711. doi: 10.1083/jcb.86.3.701. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Emr S. D., Hanley-Way S., Silhavy T. J. Suppressor mutations that restore export of a protein with a defective signal sequence. Cell. 1981 Jan;23(1):79–88. doi: 10.1016/0092-8674(81)90272-5. [DOI] [PubMed] [Google Scholar]
- Emr S. D., Silhavy T. J. Molecular components of the signal sequence that function in the initiation of protein export. J Cell Biol. 1982 Dec;95(3):689–696. doi: 10.1083/jcb.95.3.689. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Emr S. D., Silhavy T. J. Mutations affecting localization of an Escherichia coli outer membrane protein, the bacteriophage lambda receptor. J Mol Biol. 1980 Jul 25;141(1):63–90. doi: 10.1016/s0022-2836(80)80029-5. [DOI] [PubMed] [Google Scholar]
- Hall M. N., Gabay J., Schwartz M. Evidence for a coupling of synthesis and export of an outer membrane protein in Escherichia coli. EMBO J. 1983;2(1):15–19. doi: 10.1002/j.1460-2075.1983.tb01373.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hofnung M. Divergent operons and the genetic structure of the maltose B region in Escherichia coli K12. Genetics. 1974 Feb;76(2):169–184. doi: 10.1093/genetics/76.2.169. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ito K., Bassford P. J., Jr, Beckwith J. Protein localization in E. coli: is there a common step in the secretion of periplasmic and outer-membrane proteins? Cell. 1981 Jun;24(3):707–717. doi: 10.1016/0092-8674(81)90097-0. [DOI] [PubMed] [Google Scholar]
- Kumamoto C. A., Beckwith J. Mutations in a new gene, secB, cause defective protein localization in Escherichia coli. J Bacteriol. 1983 Apr;154(1):253–260. doi: 10.1128/jb.154.1.253-260.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
- Oliver D. B., Beckwith J. Regulation of a membrane component required for protein secretion in Escherichia coli. Cell. 1982 Aug;30(1):311–319. doi: 10.1016/0092-8674(82)90037-x. [DOI] [PubMed] [Google Scholar]
- Osborn M. J., Gander J. E., Parisi E., Carson J. Mechanism of assembly of the outer membrane of Salmonella typhimurium. Isolation and characterization of cytoplasmic and outer membrane. J Biol Chem. 1972 Jun 25;247(12):3962–3972. [PubMed] [Google Scholar]
- Silhavy T. J., Benson S. A., Emr S. D. Mechanisms of protein localization. Microbiol Rev. 1983 Sep;47(3):313–344. doi: 10.1128/mr.47.3.313-344.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Silhavy T. J., Shuman H. A., Beckwith J., Schwartz M. Use of gene fusions to study outer membrane protein localization in Escherichia coli. Proc Natl Acad Sci U S A. 1977 Dec;74(12):5411–5415. doi: 10.1073/pnas.74.12.5411. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Walter P., Blobel G. Signal recognition particle contains a 7S RNA essential for protein translocation across the endoplasmic reticulum. Nature. 1982 Oct 21;299(5885):691–698. doi: 10.1038/299691a0. [DOI] [PubMed] [Google Scholar]
- Walter P., Blobel G. Translocation of proteins across the endoplasmic reticulum III. Signal recognition protein (SRP) causes signal sequence-dependent and site-specific arrest of chain elongation that is released by microsomal membranes. J Cell Biol. 1981 Nov;91(2 Pt 1):557–561. doi: 10.1083/jcb.91.2.557. [DOI] [PMC free article] [PubMed] [Google Scholar]