Disease relevance of phoE

• The phoE gene of Escherichia coli codes for an outer membrane pore protein whose expression is induced under phosphate limitation [1].
• Functionally, the products of the phoE genes of E. coli K-12 and E. cloacae behave very similarly since they form pores in the outer membrane with a recognition site for negatively charged compounds and they serve as (part of) the receptor for phage TC45 [2].
• Characterization of the Salmonella typhimurium phoE gene and development of Salmonella-specific DNA probes [3].
• Characterization of the Citrobacter freundii phoE gene and development of C. freundii-specific oligonucleotides [4].

High impact information on phoE

• To study the structure-function relationship of these proteins, we have constructed a series of ompC-phoE hybrid genes in which the DNA encoding part of one protein is replaced by the corresponding part of the other gene [5].
• A phoE-lacZ hybrid gene encoding the N-terminal 300 amino acid residues of pre-PhoE protein, fused to an almost complete beta-galactosidase molecule was constructed in vitro [6].
• Molecular analysis of the promoter region of the Escherichia coli K-12 phoE gene. Identification of an element, upstream from the promoter, required for efficient expression of phoE protein [1].
• The promoter region of phoE has no homology with the consensus sequence of E. coli promoter regions, but homologous sequences with the promoter region of phoA, the structural gene for alkaline phosphatase, were observed [7].
• Complete nucleotide sequence of phoE, the structural gene for the phosphate limitation inducible outer membrane pore protein of Escherichia coli K12 [7].

Chemical compound and disease context of phoE

• Results of conventional biochemical analyses, testing of susceptibility to cephalothin, lysis by a Hafnia-specific phage, and amplification of the outer membrane protein gene phoE with species-specific primers support the identification of these strains as members of the genus Escherichia rather than Hafnia alvei [8].

Biological context of phoE

• The phoE gene was subcloned into the multicopy vector pACYC184, and the location of the gene was determined by analysis of in vitro constructed deletion plasmids and mutant plasmids generated by gamma delta insertions [2].
• The complete nucleotide sequence of the gene phoE, which codes for the phosphate limitation inducible outer membrane pore protein of Escherichia coli K12 was established [7].
• The pro operon is contiguous with the gene phoE [9].
• Effect of mutations in the -10 region of the phoE promoter in Escherichia coli on regulation of gene expression [10].
• In the upstream non-coding regions, which showed more variations among the three genes than the coding regions, conserved sequences were identified which might be involved in regulation of phoE gene expression [11].

Anatomical context of phoE

• Induction of the phoE promoter upon invasion of Salmonella typhimurium into eukaryotic cells [12].

Associations of phoE with chemical compounds

• The hybrid plasmid pLC44-11 from the Clarke and Carbon collection, which was known to carry the proA gene, was shown also to contain the phoE gene [13].
• Nucleotide sequence analysis of the DNA fragments carrying the mutations showed that the mutations all correspond to a G.C to A.T transition at the same place within the phoE gene resulting in a deduced change of amino acid residue arginine 158 into histidine [14].

Other interactions of phoE

• Two other genes, phoE and gpt, which map closely to the proBA genes in E. coli, were also found to be in close proximity to the proBA genes of V. parahaemolyticus [15].

Analytical, diagnostic and therapeutic context of phoE

• Nucleotide (nt) sequence analysis showed extensive homology of S. typhimurium phoE to the E. coli gene and suggested possible explanations for the low expression of S. typhimurium phoE in E. coli [3].
• In addition to immunodetection, the phoE-caa marker gene could be specifically detected by PCR with one primer directed to a part of the phoE sequence and a second primer that annealed to the caa insert [16].
• Southern blot analysis yielded two DNA segments which proved highly homologous to, yet distinct from, the ompC, ompF, and phoE porin genes [17].
• To study the effects of small insertions in this region of the protein on its biogenesis and characteristics, a unique restriction site was created by site-directed mutagenesis in a plasmid carrying the phoE gene and oligonucleotides of 12-74 bp were inserted [18].

1. Molecular analysis of the promoter region of the Escherichia coli K-12 phoE gene. Identification of an element, upstream from the promoter, required for efficient expression of phoE protein. Tommassen, J., Koster, M., Overduin, P. J. Mol. Biol. (1987)
2. Cloning and expression in Escherichia coli K-12 of the structural gene for outer membrane PhoE protein from Enterobacter cloacae. Verhoef, C., van Koppen, C., Overduin, P., Lugtenberg, B., Korteland, J., Tommassen, J. Gene (1984)
3. Characterization of the Salmonella typhimurium phoE gene and development of Salmonella-specific DNA probes. Spierings, G., Elders, R., van Lith, B., Hofstra, H., Tommassen, J. Gene (1992)
4. Characterization of the Citrobacter freundii phoE gene and development of C. freundii-specific oligonucleotides. Spierings, G., Ockhuijsen, C., Hofstra, H., Tommassen, J. FEMS Microbiol. Lett. (1992)
5. Localization of functional domains in E. coli K-12 outer membrane porins. Tommassen, J., van der Ley, P., van Zeijl, M., Agterberg, M. EMBO J. (1985)
6. Failure of E. coli K-12 to transport PhoE-LacZ hybrid proteins out of the cytoplasm. Tommassen, J., Leunissen, J., van Damme-Jongsten, M., Overduin, P. EMBO J. (1985)
7. Complete nucleotide sequence of phoE, the structural gene for the phosphate limitation inducible outer membrane pore protein of Escherichia coli K12. Overbeeke, N., Bergmans, H., van Mansfeld, F., Lugtenberg, B. J. Mol. Biol. (1983)
8. Prototypal diarrheagenic strains of Hafnia alvei are actually members of the genus Escherichia. Janda, J.M., Abbott, S.L., Albert, M.J. J. Clin. Microbiol. (1999)
9. Sub-cloning of the wild-type proAB region of the Escherichia coli genome. Hayzer, D.J. J. Gen. Microbiol. (1983)
10. Effect of mutations in the -10 region of the phoE promoter in Escherichia coli on regulation of gene expression. Scholten, M., Tommassen, J. Mol. Gen. Genet. (1994)
11. A comparative study on the phoE genes of three enterobacterial species. Implications for structure-function relationships in a pore-forming protein of the outer membrane. Van der Ley, P., Bekkers, A., Van Meersbergen, J., Tommassen, J. Eur. J. Biochem. (1987)
12. Induction of the phoE promoter upon invasion of Salmonella typhimurium into eukaryotic cells. Janssen, R., Verjans, G.M., Kusters, J.G., Tommassen, J. Microb. Pathog. (1995)
13. Cloning of phoE, the structural gene for the Escherichia coli phosphate limitation-inducible outer membrane pore protein. Tommassen, J., Overduin, P., Lugtenberg, B., Bergmans, H. J. Bacteriol. (1982)
14. Role of the Arg158 residue of the outer membrane PhoE pore protein of Escherichia coli K 12 in bacteriophage TC45 recognition and in channel characteristics. Korteland, J., Overbeeke, N., de Graaff, P., Overduin, P., Lugtenberg, B. Eur. J. Biochem. (1985)
15. Genetic and physical characterization of proBA genes of the marine bacterium Vibrio parahaemolyticus. Datta, A.R., Ostroff, R., MacQuillan, A.M. Appl. Environ. Microbiol. (1987)
16. Construction of phoE-caa, a novel PCR- and immunologically detectable marker gene for Pseudomonas putida. Zaat, S.A., Slegtenhorst-Eegdeman, K., Tommassen, J., Geli, V., Wijffelman, C.A., Lugtenberg, B.J. Appl. Environ. Microbiol. (1994)
17. Identification and characterization of two quiescent porin genes, nmpC and ompN, in Escherichia coli BE. Prilipov, A., Phale, P.S., Koebnik, R., Widmer, C., Rosenbusch, J.P. J. Bacteriol. (1998)
18. Insertion mutagenesis on a cell-surface-exposed region of outer membrane protein PhoE of Escherichia coli K-12. Agterberg, M., Benz, R., Tommassen, J. Eur. J. Biochem. (1987)