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Gene Review

lacZ  -  beta-D-galactosidase

Escherichia coli str. K-12 substr. MG1655

Synonyms: ECK0341, JW0335
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Disease relevance of lacZ

  • This leads to the activation of downstream promoter elements (TATA box and initiation, I, region) of three different regulated yeast promoters fused to the E. coli lacZ gene [1].
  • A strain of Escherichia coli constructed by Shapiro has a segment of Mu bacteriophage DNA inserted between the araC and lacZ genes [2].
  • Regulation of expression of genes coding for small, acid-soluble proteins of Bacillus subtilis spores: studies using lacZ gene fusions [3].
  • In vivo inversion activity was measured by using a recombinant lambda phage which contains the H2 and lacZ genes under the control of the invertible region [4].
  • The nucleotide sequences of the Klebsiella pneumoniae lacI and lacZ genes and part of the lacY gene were determined, and these genes were located and oriented relative to one another [5].

High impact information on lacZ

  • Unique to trpR-lacZ bypassing is that the 55 nt long region must be translated in frame 0 to enable bypassing into the +1 frame [6].
  • We have replaced the Hox-3.1 coding sequence with the E. coli lacZ gene by means of homologous recombination in embryonic stem cells and thus produced null mutant mice [7].
  • Ribosome bypass of the untranslated region also occurs when a segment of gene 60 is fused to lacZ and expressed in E. coli [8].
  • Expression plasmids containing the E. coli lacZ coding region preceded by a set of different ribosome-binding sites and put under transcriptional control of the leftward promoter of phage lambda (PL) were used to study the synthesis of lacZ mRNA [9].
  • With transcriptional fusions between the lacZ gene or transposon mini-Mu and the target gene, expression of lux operons could be measured in the absence of light production [10].

Chemical compound and disease context of lacZ

  • Escherichia coli strain MM18 cells containing malE-lacZ hybrid protein was reported to accumulate prolipoprotein when they were induced with maltose [Ito, K., Bassford, P. J. & Beckwith, J. (1981) Cell 24, 707-717] [11].
  • Mu dX phage was used to isolate three gene fusions to the lacZ gene (soi::lacZ; soi for superoxide radical inducible) that were induced by treatment with superoxide radical anion generators such as paraquat and plumbagin [12].
  • We measured the transcription elongation rate on two mRNA genes, i.e. infB and lacZ, and on a part of the rrnB gene under conditions when wild type (rel+) Escherichia coli and relaxed (relA) mutants were exposed to isoleucine starvation [13].
  • Here we measure the frequency of UV-induced cyclobutane pyrimidine dimers at individual nucleotides within defined portions of two Escherichia coli genes, lacl and lacZ, at various times after irradiation [14].
  • We also introduced a gene, kan, which confers kanamycin resistance, into lambda placMu50 and lambda placMu1, an analogous phage for constructing lacZ protein fusions (Bremer et al., J. Bacteriol. 158:1084-1093, 1984) [15].

Biological context of lacZ


Anatomical context of lacZ


Associations of lacZ with chemical compounds

  • Excision events that produce an in-frame fusion of lacZ to araB result in a cell (here designated Ara-Lac+) that can grow on lactose if arabinose is present as an inducer [2].
  • In some of these strains the induction (with maltose) of lamB-lacZ hybrid protein synthesis was lethal because of membrane damage resulting from an incomplete export of this protein to the outer membrane [25].
  • Using a narG-lacZ reporter fusion to evaluate narGHJI expression in vivo both the nitrate and anaerobic dependent controls were severely impaired in a himA mutant compared with the wild type strain [26].
  • The sequence determination was aided by analysis of cyanogen bromide peptides obtained from a polypeptide fragment produced by a lacZ termination mutant strain [27].
  • This approach allowed us to isolate lacZ fusions with the genes pelC, pelD, ogl and pem, encoding pectate lyases PLc and PLd, oligogalacturonate lyase and pectin methylesterase, respectively [28].

Physical interactions of lacZ

  • Substitution of the nfrB ribosome binding site with that of the E. coli lacZ gene reduced production levels of nitroreductase [29].
  • Another fusion gene was generated by inserting ceaB3 between the malE gene encoding maltose binding protein (mbp) and lacZ alpha of the pmal-c2 vector [30].
  • Analysis of lacZ transcriptional fusions shows that the KdgR-binding sites negatively affect the expression of rsmB [31].

Regulatory relationships of lacZ

  • Our findings indicate that the natural polarity of the operon (lacZ is expressed sixfold more strongly than lacA) is based on posttranslational effects and not on polarity of transcription [32].
  • Using translational fusions to lacZ we found that DNA damage caused by mitomycin C induces expression of the dnaA and dnaQ genes [33].
  • In these strains lacZ expression is regulated by the cytR repressor protein and is therefore induced by cytidine [34].
  • Mutants in this class fail to produce the lamB-lacZ hybrid protein but retain the ability to express lacY, which is located distal to the hybrid gene [25].
  • The influence of formamidopyrimidine-DNA glycosylase on the spontaneous and gamma-radiation-induced mutation spectrum of the lacZ alpha gene [35].

Other interactions of lacZ

  • Analysis of reverse mutations in lacZ and forward nonsense mutations in lacI showed that the mutA strain has higher levels of A.T----T.A and G.C----T.A transversions, and to a lesser degree A.T----C.G transversions [36].
  • This sequence is coupled to the lacZ gene of E. coli so that expression of beta-galactosidase requires ompF transcription and translation signals [20].
  • We previously showed that heat-induced translation of sigma 32-beta-galactosidase fusion protein encoded by an rpoH-lacZ gene fusion was mediated by an mRNA secondary structure formed between two 5'-proximal segments (A and B) of rpoH coding sequence spanning some 200 nt [37].
  • Induction of the lac operon in wild type Escherichia coli strains results in synthesis of a 16-kDa inner membrane protein in addition to the known products of the lacZ, lacY, and lacA genes [38].
  • Using an ompC-lacZ fusion gene, the orientation of the cis-acting upstream sequence (OmpR-binding site) with respect to the canonical -35 and -10 regions (RNA polymerase-binding site) was changed [39].

Analytical, diagnostic and therapeutic context of lacZ


  1. Nucleosome loss activates yeast downstream promoters in vivo. Han, M., Grunstein, M. Cell (1988) [Pubmed]
  2. The occurrence of heritable Mu excisions in starving cells of Escherichia coli. Foster, P.L., Cairns, J. EMBO J. (1994) [Pubmed]
  3. Regulation of expression of genes coding for small, acid-soluble proteins of Bacillus subtilis spores: studies using lacZ gene fusions. Mason, J.M., Hackett, R.H., Setlow, P. J. Bacteriol. (1988) [Pubmed]
  4. Phase variation and the Hin protein: in vivo activity measurements, protein overproduction, and purification. Bruist, M.F., Simon, M.I. J. Bacteriol. (1984) [Pubmed]
  5. Nucleotide sequence of Klebsiella pneumoniae lac genes. Buvinger, W.E., Riley, M. J. Bacteriol. (1985) [Pubmed]
  6. Frameshifting in the expression of the E. coli trpR gene occurs by the bypassing of a segment of its coding sequence. Benhar, I., Engelberg-Kulka, H. Cell (1993) [Pubmed]
  7. Homeosis in the mouse induced by a null mutation in the Hox-3.1 gene. Le Mouellic, H., Lallemand, Y., Brûlet, P. Cell (1992) [Pubmed]
  8. A nascent peptide is required for ribosomal bypass of the coding gap in bacteriophage T4 gene 60. Weiss, R.B., Huang, W.M., Dunn, D.M. Cell (1990) [Pubmed]
  9. Inefficient translation initiation causes premature transcription termination in the lacZ gene. Stanssens, P., Remaut, E., Fiers, W. Cell (1986) [Pubmed]
  10. Bacterial bioluminescence: isolation and genetic analysis of functions from Vibrio fischeri. Engebrecht, J., Nealson, K., Silverman, M. Cell (1983) [Pubmed]
  11. Post-translational modification and processing of Escherichia coli prolipoprotein in vitro. Tokunaga, M., Tokunaga, H., Wu, H.C. Proc. Natl. Acad. Sci. U.S.A. (1982) [Pubmed]
  12. Isolation of gene fusions (soi::lacZ) inducible by oxidative stress in Escherichia coli. Kogoma, T., Farr, S.B., Joyce, K.M., Natvig, D.O. Proc. Natl. Acad. Sci. U.S.A. (1988) [Pubmed]
  13. Effects of guanosine 3',5'-bisdiphosphate (ppGpp) on rate of transcription elongation in isoleucine-starved Escherichia coli. Vogel, U., Jensen, K.F. J. Biol. Chem. (1994) [Pubmed]
  14. Intragenic domains of strand-specific repair in Escherichia coli. Kunala, S., Brash, D.E. J. Mol. Biol. (1995) [Pubmed]
  15. Transposable lambda placMu bacteriophages for creating lacZ operon fusions and kanamycin resistance insertions in Escherichia coli. Bremer, E., Silhavy, T.J., Weinstock, G.M. J. Bacteriol. (1985) [Pubmed]
  16. Mutations in E coli cistrons affecting adhesion to human cells do not abolish Pap pili fiber formation. Norgren, M., Normark, S., Lark, D., O'Hanley, P., Schoolnik, G., Falkow, S., Svanborg-Edén, C., Båga, M., Uhlin, B.E. EMBO J. (1984) [Pubmed]
  17. Sequence of the lacZ gene of Escherichia coli. Kalnins, A., Otto, K., Rüther, U., Müller-Hill, B. EMBO J. (1983) [Pubmed]
  18. The art and design of genetic screens: Escherichia coli. Shuman, H.A., Silhavy, T.J. Nat. Rev. Genet. (2003) [Pubmed]
  19. Control features within the rplJL-rpoBC transcription unit of Escherichia coli. Barry, G., Squires, C.L., Squires, C. Proc. Natl. Acad. Sci. U.S.A. (1979) [Pubmed]
  20. Open reading frame expression vectors: a general method for antigen production in Escherichia coli using protein fusions to beta-galactosidase. Weinstock, G.M., ap Rhys, C., Berman, M.L., Hampar, B., Jackson, D., Silhavy, T.J., Weisemann, J., Zweig, M. Proc. Natl. Acad. Sci. U.S.A. (1983) [Pubmed]
  21. Topology of Legionella pneumophila DotA: an inner membrane protein required for replication in macrophages. Roy, C.R., Isberg, R.R. Infect. Immun. (1997) [Pubmed]
  22. The functional stability of the lacZ transcript is sensitive towards sequence alterations immediately downstream of the ribosome binding site. Petersen, C. Mol. Gen. Genet. (1987) [Pubmed]
  23. Topological characterization of an inner membrane (1-->3)-beta-D-glucan (curdlan) synthase from Agrobacterium sp. strain ATCC31749. Karnezis, T., Epa, V.C., Stone, B.A., Stanisich, V.A. Glycobiology (2003) [Pubmed]
  24. Ethyl nitrosourea and methyl methanesulfonate mutagenicity in sperm and testicular germ cells of lacZ transgenic mice (Muta Mouse). Suzuki, T., Itoh, S., Takemoto, N., Yajima, N., Miura, M., Hayashi, M., Shimada, H., Sofuni, T. Mutat. Res. (1997) [Pubmed]
  25. Mutations that affect lamB gene expression at a posttranscriptional level. Schwartz, M., Roa, M., Débarbouillé, M. Proc. Natl. Acad. Sci. U.S.A. (1981) [Pubmed]
  26. Activation of the Escherichia coli nitrate reductase (narGHJI) operon by NarL and Fnr requires integration host factor. Schröder, I., Darie, S., Gunsalus, R.P. J. Biol. Chem. (1993) [Pubmed]
  27. Amino acid sequence of beta-galactosidase. XI. Peptide ordering procedures and the complete sequence. Fowler, A.V., Zabin, I. J. Biol. Chem. (1978) [Pubmed]
  28. Isolation of Erwinia chrysanthemi mutants altered in pectinolytic enzyme production. Hugouvieux-Cotte-Pattat, N., Robert-Baudouy, J. Mol. Microbiol. (1989) [Pubmed]
  29. Physical characterisation of the Escherichia coli B gene encoding nitroreductase and its over-expression in Escherichia coli K12. Michael, N.P., Brehm, J.K., Anlezark, G.M., Minton, N.P. FEMS Microbiol. Lett. (1994) [Pubmed]
  30. A monoclonal antibody generated against a recombinant peptide fragment of the B3 domain of carcinoembryonic antigen reacts with intact carcinoembryonic antigen. Hagendorff, G., Hanes, J., von der Kammer, H., Scheit, K.H. Biochim. Biophys. Acta (1995) [Pubmed]
  31. kdgREcc negatively regulates genes for pectinases, cellulase, protease, HarpinEcc, and a global RNA regulator in Erwinia carotovora subsp. carotovora. Liu, Y., Jiang, G., Cui, Y., Mukherjee, A., Ma, W.L., Chatterjee, A.K. J. Bacteriol. (1999) [Pubmed]
  32. Transcription and decay of the lac messenger: role of an intergenic terminator. Murakawa, G.J., Kwan, C., Yamashita, J., Nierlich, D.P. J. Bacteriol. (1991) [Pubmed]
  33. Expression of the dnaN and dnaQ genes of Escherichia coli is inducible by mitomycin C. Kaasch, M., Kaasch, J., Quiñones, A. Mol. Gen. Genet. (1989) [Pubmed]
  34. Fusion of the lac genes to the promotor for the cytidine deaminase gene of Escherichia coli K-12. Josephsen, J., Hammer-Jespersen, K. Mol. Gen. Genet. (1981) [Pubmed]
  35. The influence of formamidopyrimidine-DNA glycosylase on the spontaneous and gamma-radiation-induced mutation spectrum of the lacZ alpha gene. Kuipers, G.K., Poldervaart, H.A., Slotman, B.J., Lafleur, M.V. Mutat. Res. (1999) [Pubmed]
  36. mutA and mutC: two mutator loci in Escherichia coli that stimulate transversions. Michaels, M.L., Cruz, C., Miller, J.H. Proc. Natl. Acad. Sci. U.S.A. (1990) [Pubmed]
  37. A distinct segment of the sigma 32 polypeptide is involved in DnaK-mediated negative control of the heat shock response in Escherichia coli. Nagai, H., Yuzawa, H., Kanemori, M., Yura, T. Proc. Natl. Acad. Sci. U.S.A. (1994) [Pubmed]
  38. Coordinate expression of a small polypeptide with the lactose carrier of Escherichia coli. Lagarias, D.M., Villarejo, M. J. Biol. Chem. (1985) [Pubmed]
  39. Activation of the ompC gene by the OmpR protein in Escherichia coli. The cis-acting upstream sequence can function in both orientations with respect to the canonical promoter. Maeda, S., Mizuno, T. J. Biol. Chem. (1988) [Pubmed]
  40. Regulation of the ompC gene of Escherichia coli. Involvement of three tandem promoters. Ikenaka, K., Ramakrishnan, G., Inouye, M., Tsung, K., Inouye, M. J. Biol. Chem. (1986) [Pubmed]
  41. Different mechanisms of thioredoxin in its reduced and oxidized forms in defense against hydrogen peroxide in Escherichia coli. Takemoto, T., Zhang, Q.M., Yonei, S. Free Radic. Biol. Med. (1998) [Pubmed]
  42. Effect of heme and oxygen availability on hemA gene expression in Escherichia coli: role of the fnr, arcA, and himA gene products. Darie, S., Gunsalus, R.P. J. Bacteriol. (1994) [Pubmed]
  43. Nucleotide sequence of the control regions for the glnA and glnL genes of Salmonella typhimurium. Hanau, R., Koduri, R.K., Ho, N., Brenchley, J.E. J. Bacteriol. (1983) [Pubmed]
  44. The relation between translation and mRNA degradation in the lacZ gene. Yarchuk, O., Iost, I., Dreyfus, M. Biochimie (1991) [Pubmed]
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