Skip to main content
Journal of Bacteriology logoLink to Journal of Bacteriology
. 1991 Sep;173(18):5763–5770. doi: 10.1128/jb.173.18.5763-5770.1991

Identification of the Escherichia coli sohB gene, a multicopy suppressor of the HtrA (DegP) null phenotype.

L Baird 1, B Lipinska 1, S Raina 1, C Georgopoulos 1
PMCID: PMC208308  PMID: 1885549

Abstract

We cloned and sequenced the sohB gene of Escherichia coli. The temperature-sensitive phenotype of bacteria that carry a Tn10 insertion in the htrA (degP) gene is relieved when the sohB gene is present in the cell on a multicopy plasmid (30 to 50 copies per cell). The htrA gene encodes a periplasmic protease required for bacterial viability only at high temperature, i.e., above 39 degrees C. The sohB gene maps to 28 min on the E. coli chromosome, precisely between the topA and btuR genes. The gene encodes a 39,000-Mr precursor protein which is processed to a 37,000-Mr mature form. Sequencing of a DNA fragment containing the gene revealed an open reading frame which could encode a protein of Mr 39,474 with a predicted signal sequence cleavage site between amino acids 22 and 23. Cleavage at this site would reduce the size of the processed protein to 37,474 Mr. The predicted protein encoded by the open reading frame has homology with the inner membrane enzyme protease IV of E. coli, which digests cleaved signal peptides. Therefore, it is possible that the sohB gene encodes a previously undiscovered periplasmic protease in E. coli that, when overexpressed, can partially compensate for the missing HtrA protein function.

Full text

PDF
5765

Images in this article

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Ang D., Chandrasekhar G. N., Zylicz M., Georgopoulos C. Escherichia coli grpE gene codes for heat shock protein B25.3, essential for both lambda DNA replication at all temperatures and host growth at high temperature. J Bacteriol. 1986 Jul;167(1):25–29. doi: 10.1128/jb.167.1.25-29.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Baird L., Georgopoulos C. Identification, cloning, and characterization of the Escherichia coli sohA gene, a suppressor of the htrA (degP) null phenotype. J Bacteriol. 1990 Mar;172(3):1587–1594. doi: 10.1128/jb.172.3.1587-1594.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Eisenberg D., Schwarz E., Komaromy M., Wall R. Analysis of membrane and surface protein sequences with the hydrophobic moment plot. J Mol Biol. 1984 Oct 15;179(1):125–142. doi: 10.1016/0022-2836(84)90309-7. [DOI] [PubMed] [Google Scholar]
  4. Erickson J. W., Gross C. A. Identification of the sigma E subunit of Escherichia coli RNA polymerase: a second alternate sigma factor involved in high-temperature gene expression. Genes Dev. 1989 Sep;3(9):1462–1471. doi: 10.1101/gad.3.9.1462. [DOI] [PubMed] [Google Scholar]
  5. Erickson J. W., Vaughn V., Walter W. A., Neidhardt F. C., Gross C. A. Regulation of the promoters and transcripts of rpoH, the Escherichia coli heat shock regulatory gene. Genes Dev. 1987 Jul;1(5):419–432. doi: 10.1101/gad.1.5.419. [DOI] [PubMed] [Google Scholar]
  6. Groisman E. A., Casadaban M. J. Mini-mu bacteriophage with plasmid replicons for in vivo cloning and lac gene fusing. J Bacteriol. 1986 Oct;168(1):357–364. doi: 10.1128/jb.168.1.357-364.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Groisman E. A., Pagratis N., Casadaban M. J. Genome mapping and protein coding region identification using bacteriophage Mu. Gene. 1991 Mar 1;99(1):1–7. doi: 10.1016/0378-1119(91)90026-8. [DOI] [PubMed] [Google Scholar]
  8. Grossman A. D., Erickson J. W., Gross C. A. The htpR gene product of E. coli is a sigma factor for heat-shock promoters. Cell. 1984 Sep;38(2):383–390. doi: 10.1016/0092-8674(84)90493-8. [DOI] [PubMed] [Google Scholar]
  9. Hendrix R. W., Casjens S. R. Protein fusion: a novel reaction in bacteriophage lambda head assembly. Proc Natl Acad Sci U S A. 1974 Apr;71(4):1451–1455. doi: 10.1073/pnas.71.4.1451. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Henikoff S. Unidirectional digestion with exonuclease III creates targeted breakpoints for DNA sequencing. Gene. 1984 Jun;28(3):351–359. doi: 10.1016/0378-1119(84)90153-7. [DOI] [PubMed] [Google Scholar]
  11. Hong G. F. A systemic DNA sequencing strategy. J Mol Biol. 1982 Jul 5;158(3):539–549. doi: 10.1016/0022-2836(82)90213-3. [DOI] [PubMed] [Google Scholar]
  12. Ichihara S., Suzuki T., Suzuki M., Mizushima S. Molecular cloning and sequencing of the sppA gene and characterization of the encoded protease IV, a signal peptide peptidase, of Escherichia coli. J Biol Chem. 1986 Jul 15;261(20):9405–9411. [PubMed] [Google Scholar]
  13. Kiino D. R., Phillips G. J., Silhavy T. J. Increased expression of the bifunctional protein PrlF suppresses overproduction lethality associated with exported beta-galactosidase hybrid proteins in Escherichia coli. J Bacteriol. 1990 Jan;172(1):185–192. doi: 10.1128/jb.172.1.185-192.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Klein P., Kanehisa M., DeLisi C. The detection and classification of membrane-spanning proteins. Biochim Biophys Acta. 1985 May 28;815(3):468–476. doi: 10.1016/0005-2736(85)90375-x. [DOI] [PubMed] [Google Scholar]
  15. Kohara Y., Akiyama K., Isono K. The physical map of the whole E. coli chromosome: application of a new strategy for rapid analysis and sorting of a large genomic library. Cell. 1987 Jul 31;50(3):495–508. doi: 10.1016/0092-8674(87)90503-4. [DOI] [PubMed] [Google Scholar]
  16. Kyte J., Doolittle R. F. A simple method for displaying the hydropathic character of a protein. J Mol Biol. 1982 May 5;157(1):105–132. doi: 10.1016/0022-2836(82)90515-0. [DOI] [PubMed] [Google Scholar]
  17. 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]
  18. Lipinska B., Fayet O., Baird L., Georgopoulos C. Identification, characterization, and mapping of the Escherichia coli htrA gene, whose product is essential for bacterial growth only at elevated temperatures. J Bacteriol. 1989 Mar;171(3):1574–1584. doi: 10.1128/jb.171.3.1574-1584.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Lipinska B., Sharma S., Georgopoulos C. Sequence analysis and regulation of the htrA gene of Escherichia coli: a sigma 32-independent mechanism of heat-inducible transcription. Nucleic Acids Res. 1988 Nov 11;16(21):10053–10067. doi: 10.1093/nar/16.21.10053. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Lipinska B., Zylicz M., Georgopoulos C. The HtrA (DegP) protein, essential for Escherichia coli survival at high temperatures, is an endopeptidase. J Bacteriol. 1990 Apr;172(4):1791–1797. doi: 10.1128/jb.172.4.1791-1797.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Lundrigan M. D., Kadner R. J. Altered cobalamin metabolism in Escherichia coli btuR mutants affects btuB gene regulation. J Bacteriol. 1989 Jan;171(1):154–161. doi: 10.1128/jb.171.1.154-161.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Mohana Rao J. K., Argos P. A conformational preference parameter to predict helices in integral membrane proteins. Biochim Biophys Acta. 1986 Jan 30;869(2):197–214. doi: 10.1016/0167-4838(86)90295-5. [DOI] [PubMed] [Google Scholar]
  23. Neidhardt F. C., VanBogelen R. A., Vaughn V. The genetics and regulation of heat-shock proteins. Annu Rev Genet. 1984;18:295–329. doi: 10.1146/annurev.ge.18.120184.001455. [DOI] [PubMed] [Google Scholar]
  24. Oden K. L., DeVeaux L. C., Vibat C. R., Cronan J. E., Jr, Gennis R. B. Genomic replacement in Escherichia coli K-12 using covalently closed circular plasmid DNA. Gene. 1990 Nov 30;96(1):29–36. doi: 10.1016/0378-1119(90)90337-q. [DOI] [PubMed] [Google Scholar]
  25. Pacaud M. Purification and characterization of two novel proteolytic enzymes in membranes of Escherichia coli. Protease IV and protease V. J Biol Chem. 1982 Apr 25;257(8):4333–4339. [PubMed] [Google Scholar]
  26. Pearson W. R., Lipman D. J. Improved tools for biological sequence comparison. Proc Natl Acad Sci U S A. 1988 Apr;85(8):2444–2448. doi: 10.1073/pnas.85.8.2444. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Ray P., Murialdo H. The role of gene Nu3 in bacteriophage lambda head morphogenesis. Virology. 1975 Mar;64(1):247–263. doi: 10.1016/0042-6822(75)90096-3. [DOI] [PubMed] [Google Scholar]
  28. Spence J., Georgopoulos C. Purification and properties of the Escherichia coli heat shock protein, HtpG. J Biol Chem. 1989 Mar 15;264(8):4398–4403. [PubMed] [Google Scholar]
  29. Strauch K. L., Beckwith J. An Escherichia coli mutation preventing degradation of abnormal periplasmic proteins. Proc Natl Acad Sci U S A. 1988 Mar;85(5):1576–1580. doi: 10.1073/pnas.85.5.1576. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Strauch K. L., Johnson K., Beckwith J. Characterization of degP, a gene required for proteolysis in the cell envelope and essential for growth of Escherichia coli at high temperature. J Bacteriol. 1989 May;171(5):2689–2696. doi: 10.1128/jb.171.5.2689-2696.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Studier F. W., Moffatt B. A. Use of bacteriophage T7 RNA polymerase to direct selective high-level expression of cloned genes. J Mol Biol. 1986 May 5;189(1):113–130. doi: 10.1016/0022-2836(86)90385-2. [DOI] [PubMed] [Google Scholar]
  32. Suzuki T., Itoh A., Ichihara S., Mizushima S. Characterization of the sppA gene coding for protease IV, a signal peptide peptidase of Escherichia coli. J Bacteriol. 1987 Jun;169(6):2523–2528. doi: 10.1128/jb.169.6.2523-2528.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Tse-Dinh Y. C., Wang J. C. Complete nucleotide sequence of the topA gene encoding Escherichia coli DNA topoisomerase I. J Mol Biol. 1986 Oct 5;191(3):321–331. doi: 10.1016/0022-2836(86)90129-4. [DOI] [PubMed] [Google Scholar]
  34. Wang Q. P., Kaguni J. M. A novel sigma factor is involved in expression of the rpoH gene of Escherichia coli. J Bacteriol. 1989 Aug;171(8):4248–4253. doi: 10.1128/jb.171.8.4248-4253.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. von Heijne G. A new method for predicting signal sequence cleavage sites. Nucleic Acids Res. 1986 Jun 11;14(11):4683–4690. doi: 10.1093/nar/14.11.4683. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Journal of Bacteriology are provided here courtesy of American Society for Microbiology (ASM)

RESOURCES