Gene Symbol: pal
Description: peptidoglycan-associated outer membrane lipoprotein
Alias: ECK0730, JW0731, excC
Species: Escherichia coli str. K-12 substr. MG1655

Top Publications

  1. Vines E, Marolda C, Balachandran A, Valvano M. Defective O-antigen polymerization in tolA and pal mutants of Escherichia coli in response to extracytoplasmic stress. J Bacteriol. 2005;187:3359-68 pubmed
    ..In this work, delta tolA and delta pal mutants of E...
  2. Cascales E, Lloubes R. Deletion analyses of the peptidoglycan-associated lipoprotein Pal reveals three independent binding sequences including a TolA box. Mol Microbiol. 2004;51:873-85 pubmed
    The Tol-Pal system of the Escherichia coli cell envelope is composed of five proteins...
  3. Bouveret E, Derouiche R, Rigal A, Lloubes R, Lazdunski C, Benedetti H. Peptidoglycan-associated lipoprotein-TolB interaction. A possible key to explaining the formation of contact sites between the inner and outer membranes of Escherichia coli. J Biol Chem. 1995;270:11071-7 pubmed
    ..These two approaches led to the same result and demonstrated for the first time that a component of the Tol system, TolB, interacts with a protein located in the outer membrane, the peptidoglycan-associated lipoprotein. ..
  4. Germon P, Ray M, Vianney A, Lazzaroni J. Energy-dependent conformational change in the TolA protein of Escherichia coli involves its N-terminal domain, TolQ, and TolR. J Bacteriol. 2001;183:4110-4 pubmed
    ..We repeated those experiments in outer membrane mutants such as lpp, pal, and Delta rfa mutants: the behavior of TolA in lpp mutants was similar to that observed with the parental strain...
  5. Ray M, Germon P, Vianney A, Portalier R, Lazzaroni J. Identification by genetic suppression of Escherichia coli TolB residues important for TolB-Pal interaction. J Bacteriol. 2000;182:821-4 pubmed
    The Tol-Pal system of Escherichia coli is involved in maintaining outer membrane stability. Mutations in tolQ, tolR, tolA, tolB, or pal genes result in sensitivity to bile salts and the leakage of periplasmic proteins...
  6. Bonsor D, Grishkovskaya I, Dodson E, Kleanthous C. Molecular mimicry enables competitive recruitment by a natively disordered protein. J Am Chem Soc. 2007;129:4800-7 pubmed
    We report the crystal structure of the Escherichia coli TolB-Pal complex, a protein-protein complex involved in maintaining the integrity of the outer membrane (OM) in all Gram-negative bacteria that is parasitized by colicins (protein ..
  7. Vianney A, Jubelin G, Renault S, Dorel C, Lejeune P, Lazzaroni J. Escherichia coli tol and rcs genes participate in the complex network affecting curli synthesis. Microbiology. 2005;151:2487-97 pubmed
    ..Furthermore, it is shown that the defect in cell motility observed in the tol mutants depends on RcsB and RcsA. ..
  8. Bonsor D, Hecht O, Vankemmelbeke M, Sharma A, Krachler A, Housden N, et al. Allosteric beta-propeller signalling in TolB and its manipulation by translocating colicins. EMBO J. 2009;28:2846-57 pubmed publisher
    ..In contrast to ColE9, binding of the OM lipoprotein Pal to the same site induces conformational changes that sequester the TolA box to the TolB surface in which it ..
  9. Cascales E, Lloubes R, Sturgis J. The TolQ-TolR proteins energize TolA and share homologies with the flagellar motor proteins MotA-MotB. Mol Microbiol. 2001;42:795-807 pubmed
    The Tol-Pal system of Escherichia coli is required for the maintenance of outer membrane stability...

More Information


  1. Bernadac A, Gavioli M, Lazzaroni J, Raina S, Lloubes R. Escherichia coli tol-pal mutants form outer membrane vesicles. J Bacteriol. 1998;180:4872-8 pubmed
    Mutations in the tol-pal genes induce pleiotropic effects such as release of periplasmic proteins into the extracellular medium and hypersensitivity to drugs and detergents...
  2. Gerding M, Ogata Y, Pecora N, Niki H, de Boer P. The trans-envelope Tol-Pal complex is part of the cell division machinery and required for proper outer-membrane invagination during cell constriction in E. coli. Mol Microbiol. 2007;63:1008-25 pubmed
    ..The Tol-Pal system is energized by proton motive force and is well conserved in Gram-negative bacteria...
  3. Liang M, Bagchi A, Warren H, Tehan M, Trigilio J, Beasley Topliffe L, et al. Bacterial peptidoglycan-associated lipoprotein: a naturally occurring toll-like receptor 2 agonist that is shed into serum and has synergy with lipopolysaccharide. J Infect Dis. 2005;191:939-48 pubmed
    ..Peptidoglycan-associated lipoprotein (PAL) is a ubiquitous gram-negative bacterial outer-membrane protein that is shed by bacteria into the circulation of ..
  4. Robichon C, Vidal Ingigliardi D, Pugsley A. Depletion of apolipoprotein N-acyltransferase causes mislocalization of outer membrane lipoproteins in Escherichia coli. J Biol Chem. 2005;280:974-83 pubmed
    ..Schmid, M. B., and Wu, H. C. (1993) J. Biol. Chem. 268, 16551-16556) was found to carry a mutation causing a single glutamate to lysine substitution at a highly conserved position in the last predicted periplasmic loop of the protein. ..
  5. Mizutani M, Mukaiyama K, Xiao J, Mori M, Satou R, Narita S, et al. Functional differentiation of structurally similar membrane subunits of the ABC transporter LolCDE complex. FEBS Lett. 2013;587:23-9 pubmed publisher
    A photo-sensitive amino acid analogue was introduced into an outer membrane lipoprotein, Pal, and then subjected to photo-crosslinking with the lipoprotein-specific ABC transporter LolCDE...
  6. Han M, Lee S, Hong S. Comparative analysis of envelope proteomes in Escherichia coli B and K-12 strains. J Microbiol Biotechnol. 2012;22:470-8 pubmed
    ..Thus, these findings suggest that E. coli K-12 and its derivatives will be more favorable strains in certain biotechnological applications, such as cell surface display or membrane engineering studies. ..
  7. Chen R, Henning U. Nucleotide sequence of the gene for the peptidoglycan-associated lipoprotein of Escherichia coli K12. Eur J Biochem. 1987;163:73-7 pubmed
    ..with all the properties, including the amino acid composition, of the peptidoglycan-associated lipoprotein (PAL) [Mizuno, T. (1979) J. Biochem. (Tokyo) 86, 991-1000]. Therefore, the cloned gene is the pal gene...
  8. Rigal A, Bouveret E, Lloubes R, Lazdunski C, Benedetti H. The TolB protein interacts with the porins of Escherichia coli. J Bacteriol. 1997;179:7274-9 pubmed
    ..It is partially membrane associated through an interaction with the outer membrane lipoprotein PAL (peptidoglycan-associated lipoprotein), which also belongs to the Tol system...
  9. Derouiche R, Benedetti H, Lazzaroni J, Lazdunski C, Lloubes R. Protein complex within Escherichia coli inner membrane. TolA N-terminal domain interacts with TolQ and TolR proteins. J Biol Chem. 1995;270:11078-84 pubmed
    ..Since these two TolA derivatives still formed specific complexes with TolR derivatives still formed specific complexes with TolR and TolQ, we concluded that the TolA N-terminal domain interacted with these proteins. ..
  10. Mizuno T. A novel peptidoglycan-associated lipoprotein found in the cell envelope of Pseudomonas aeruginosa and Escherichia coli. J Biochem. 1979;86:991-1000 pubmed
    ..aeruginosa PAO are a novel type of lipoprotein. All nine gram-negative bacteria tested, including enteric and non-enteric bacteria, contained a similar protein of apparent molecular weight 21,000 as a peptidoglycan-protein complex. ..
  11. Clavel T, Germon P, Vianney A, Portalier R, Lazzaroni J. TolB protein of Escherichia coli K-12 interacts with the outer membrane peptidoglycan-associated proteins Pal, Lpp and OmpA. Mol Microbiol. 1998;29:359-67 pubmed
    The Tol-Pal proteins of Escherichia coli are involved in maintaining outer membrane integrity. Transmembrane domains of TolQ, TolR and TolA interact in the cytoplasmic membrane, while TolB and Pal form a complex near the outer membrane...
  12. Loftus S, Walker D, Mat M, Bonsor D, James R, Moore G, et al. Competitive recruitment of the periplasmic translocation portal TolB by a natively disordered domain of colicin E9. Proc Natl Acad Sci U S A. 2006;103:12353-8 pubmed publisher
    ..that runs through the beta-propeller and that constitutes the binding site of peptidoglycan-associated lipoprotein (Pal). Pal is a globular binding partner of TolB, and their association is known to be important for OM integrity...
  13. Hizukuri Y, Morton J, Yakushi T, Kojima S, Homma M. The peptidoglycan-binding (PGB) domain of the Escherichia coli pal protein can also function as the PGB domain in E. coli flagellar motor protein MotB. J Biochem. 2009;146:219-29 pubmed publisher
    ..and constructed a chimeric MotB protein which was replaced with the peptidoglycan-associated lipoprotein Pal. Although this chimera could not restore motility to a motB strain, we were able to isolate two motile revertants...
  14. Gully D, Bouveret E. A protein network for phospholipid synthesis uncovered by a variant of the tandem affinity purification method in Escherichia coli. Proteomics. 2006;6:282-93 pubmed
    ..Taken together, these results describe an integrated protein network that could be involved in the coordination of phospholipid metabolism. ..
  15. Cascales E, Bernadac A, Gavioli M, Lazzaroni J, Lloubes R. Pal lipoprotein of Escherichia coli plays a major role in outer membrane integrity. J Bacteriol. 2002;184:754-9 pubmed
    The Tol-Pal system of gram-negative bacteria is composed of five proteins...
  16. Lazdunski C, Bouveret E, Rigal A, Journet L, Lloubes R, Benedetti H. Colicin import into Escherichia coli cells. J Bacteriol. 1998;180:4993-5002 pubmed
  17. Sturgis J. Organisation and evolution of the tol-pal gene cluster. J Mol Microbiol Biotechnol. 2001;3:113-22 pubmed
    The genomic context and phylogenetic distribution of the tol-pal gene cluster and homologues to its various components have been investigated...
  18. Cascales E, Gavioli M, Sturgis J, Lloubes R. Proton motive force drives the interaction of the inner membrane TolA and outer membrane pal proteins in Escherichia coli. Mol Microbiol. 2000;38:904-15 pubmed
    The Tol-Pal system of the Escherichia coli envelope is formed from the inner membrane TolQ, TolR and TolA proteins, the periplasmic TolB protein and the outer membrane Pal lipoprotein...
  19. Vianney A, Muller M, Clavel T, Lazzaroni J, Portalier R, Webster R. Characterization of the tol-pal region of Escherichia coli K-12: translational control of tolR expression by TolQ and identification of a new open reading frame downstream of pal encoding a periplasmic protein. J Bacteriol. 1996;178:4031-8 pubmed
    The TolQ, TolR, TolA, TolB, and Pal proteins appear to function in maintaining the integrity of the outer membrane, as well as facilitating the uptake of the group A colicins and the DNA of the infecting filamentous bacteriophages...
  20. Karlsson F, Borrebaeck C, Nilsson N, Malmborg Hager A. The mechanism of bacterial infection by filamentous phages involves molecular interactions between TolA and phage protein 3 domains. J Bacteriol. 2003;185:2628-34 pubmed
    ..The multiple roles for each of the separate g3p and TolA domains imply a delicate interaction network during the phage infection process and a model for the infection mechanism is hypothesized...
  21. Watanabe S, Oguchi Y, Yokota N, Tokuda H. Large-scale preparation of the homogeneous LolA lipoprotein complex and efficient in vitro transfer of lipoproteins to the outer membrane in a LolB-dependent manner. Protein Sci. 2007;16:2741-9 pubmed
    ..We report here that the coexpression of LolA and outer membrane-specific lipoprotein Pal from a very efficient plasmid causes the unusual accumulation of the LolA-Pal complex in the periplasm...
  22. Bouveret E, Benedetti H, Rigal A, Loret E, Lazdunski C. In vitro characterization of peptidoglycan-associated lipoprotein (PAL)-peptidoglycan and PAL-TolB interactions. J Bacteriol. 1999;181:6306-11 pubmed
    The Tol-peptidoglycan-associated lipoprotein (PAL) system of Escherichia coli is a multiprotein complex of the envelope involved in maintaining outer membrane integrity...
  23. Lloubes R, Cascales E, Walburger A, Bouveret E, Lazdunski C, Bernadac A, et al. The Tol-Pal proteins of the Escherichia coli cell envelope: an energized system required for outer membrane integrity?. Res Microbiol. 2001;152:523-9 pubmed
    ..However, outer membrane proteins together with the Tol-Pal and TonB systems have been exploited for the entry of macromolecules such as bacteriocins and phage DNA through the ..
  24. Michel L, Shaw J, MacPherson V, Barnard D, Bettinger J, D Arcy B, et al. Dual orientation of the outer membrane lipoprotein Pal in Escherichia coli. Microbiology. 2015;161:1251-9 pubmed publisher
    Peptidoglycan associated lipoprotein (Pal) of Escherichia coli (E. coli) is a characteristic bacterial lipoprotein, with an N-terminal lipid moiety anchoring it to the outer membrane...
  25. Journet L, Bouveret E, Rigal A, Lloubes R, Lazdunski C, Benedetti H. Import of colicins across the outer membrane of Escherichia coli involves multiple protein interactions in the periplasm. Mol Microbiol. 2001;42:331-44 pubmed
    Several proteins of the Tol/Pal system are required for group A colicin import into Escherichia coli. Colicin A interacts with TolA and TolB via distinct regions of its N-terminal domain...
  26. Tajima T, Yokota N, Matsuyama S, Tokuda H. Genetic analyses of the in vivo function of LolA, a periplasmic chaperone involved in the outer membrane localization of Escherichia coli lipoproteins. FEBS Lett. 1998;439:51-4 pubmed
    ..Depletion of LolA caused a severe growth defect, and impaired the outer membrane localization of Lpp and Pal, another outer membrane lipoprotein...
  27. Levengood S, Webster R. Nucleotide sequences of the tolA and tolB genes and localization of their products, components of a multistep translocation system in Escherichia coli. J Bacteriol. 1989;171:6600-9 pubmed
    ..The larger protein of 47.5 kilodaltons appears to be associated with the membrane fractions. The smaller protein is 43 kilodaltons in size and is found with the periplasmic components of the cell. ..
  28. Davies J, Reeves P. Genetics of resistance to colicins in Escherichia coli K-12: cross-resistance among colicins of group B. J Bacteriol. 1975;123:96-101 pubmed
    ..Sodium dodecyl sulfate-polyacrylamide gel electrophoresis has revealed substantial changes in the composition of the outer membrane proteins of exbB and tonB mutants. ..
  29. Walburger A, Lazdunski C, Corda Y. The Tol/Pal system function requires an interaction between the C-terminal domain of TolA and the N-terminal domain of TolB. Mol Microbiol. 2002;44:695-708 pubmed
    The Tol/Pal system of Escherichia coli is composed of the YbgC, TolQ, TolA, TolR, TolB, Pal and YbgF proteins...
  30. Fognini Lefebvre N, Lazzaroni J, Portalier R. tolA, tolB and excC, three cistrons involved in the control of pleiotropic release of periplasmic proteins by Escherichia coli K12. Mol Gen Genet. 1987;209:391-5 pubmed
    ..Furthermore, we identified a third cistron, excC, involved in the excretion of periplasmic enzymes but distinct from the two others.
  31. McBroom A, Johnson A, Vemulapalli S, Kuehn M. Outer membrane vesicle production by Escherichia coli is independent of membrane instability. J Bacteriol. 2006;188:5385-92 pubmed
    ..Detergent sensitivity, leakiness, and growth characteristics of the novel vesiculation mutant strains did not correlate with vesiculation levels, demonstrating that vesicle production is not predictive of envelope instability. ..
  32. Click E, Webster R. Filamentous phage infection: required interactions with the TolA protein. J Bacteriol. 1997;179:6464-71 pubmed
    ..The essential interaction of TolA domain III with phage via gene III protein appears to require interaction with a third component, either the pilus tip or a periplasmic entity. ..
  33. Sun T, Webster R. fii, a bacterial locus required for filamentous phage infection and its relation to colicin-tolerant tolA and tolB. J Bacteriol. 1986;165:107-15 pubmed
    ..The product of tolA has been identified tentatively as a 51-kilodalton protein. Data from cloning, Tn5 mutagenesis, and P1 transduction studies are consistent with the gene order sucA-fii-tolA-tolB-aroG near 17 min on the E. coli map. ..
  34. Lazzaroni J, Fognini Lefebvre N, Portalier R. Cloning of the excC and excD genes involved in the release of periplasmic proteins by Escherichia coli K12. Mol Gen Genet. 1989;218:460-4 pubmed
    ..and exc mutations were located either in the previously described tolA and tolB genes or in the newly characterized excC and excD genes...
  35. Lazzaroni J, Portalier R. The excC gene of Escherichia coli K-12 required for cell envelope integrity encodes the peptidoglycan-associated lipoprotein (PAL). Mol Microbiol. 1992;6:735-42 pubmed
    The excC mutants of Escherichia coli are hypersensitive to drugs such as cholic acid and release periplasmic proteins into the extracellular medium. A 1884 bp fragment carrying the excC gene was isolated and sequenced...