Search tips
Search criteria 


Logo of jbacterPermissionsJournals.ASM.orgJournalJB ArticleJournal InfoAuthorsReviewers
J Bacteriol. 1997 September; 179(17): 5465–5470.
PMCID: PMC179418

Outer membrane localization of murein hydrolases: MltA, a third lipoprotein lytic transglycosylase in Escherichia coli.


Lytic transglycosylases are a unique lysozyme-like class of murein hydrolases believed to be important for growth of Escherichia coli. A membrane-bound lytic transglycosylase with an apparent molecular mass of 38 kDa, which was designated Mlt38, has previously been purified and characterized (A. Ursinus and J.-V. Höltje, J. Bacteriol. 176:338-343, 1994). On the basis of four tryptic peptides, the gene mltA was mapped at 63 min on the chromosomal map of E. coli K-12 and cloned by reverse genetics. The open reading frame was found to contain a typical lipoprotein consensus sequence, and the lipoprotein nature of the gene product was demonstrated by [3H]palmitate labeling. On the basis of the distribution of MltA in membrane fractions obtained by sucrose gradient centrifugation, a localization in the outer membrane is indicated. Overexpression of MltA at 30 degrees C, the optimal temperature for enzyme activity, but not at 37 degrees C results in the formation of spheroplasts. Not only a deletion mutant in mltA, but also double mutants in mltA and one of the two other well-characterized lytic transglycosylases (either sltY or mltB), as well as a triple mutant in all three enzymes, showed no obvious phenotype. However, dramatic changes in the structure of the murein sacculus indicate that lytic transglycosylases are involved in maturation of the murein sacculus.

Full Text

The Full Text of this article is available as a PDF (215K).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Altschul SF, Gish W, Miller W, Myers EW, Lipman DJ. Basic local alignment search tool. J Mol Biol. 1990 Oct 5;215(3):403–410. [PubMed]
  • Barbas JA, Díaz J, Rodríguez-Tébar A, Vázquez D. Specific location of penicillin-binding proteins within the cell envelope of Escherichia coli. J Bacteriol. 1986 Jan;165(1):269–275. [PMC free article] [PubMed]
  • Bayer MH, Keck W, Bayer ME. Localization of penicillin-binding protein 1b in Escherichia coli: immunoelectron microscopy and immunotransfer studies. J Bacteriol. 1990 Jan;172(1):125–135. [PMC free article] [PubMed]
  • Betzner AS, Keck W. Molecular cloning, overexpression and mapping of the slt gene encoding the soluble lytic transglycosylase of Escherichia coli. Mol Gen Genet. 1989 Nov;219(3):489–491. [PubMed]
  • Bishop RE, Weiner JH. Complementation of growth defect in an ampC deletion mutant of Escherichia coli. FEMS Microbiol Lett. 1993 Dec 15;114(3):349–354. [PubMed]
  • Casadaban MJ, Cohen SN. Analysis of gene control signals by DNA fusion and cloning in Escherichia coli. J Mol Biol. 1980 Apr;138(2):179–207. [PubMed]
  • Clarke L, Carbon J. A colony bank containing synthetic Col El hybrid plasmids representative of the entire E. coli genome. Cell. 1976 Sep;9(1):91–99. [PubMed]
  • Csonka LN, Clark AJ. Deletions generated by the transposon Tn10 in the srl recA region of the Escherichia coli K-12 chromosome. Genetics. 1979 Oct;93(2):321–343. [PubMed]
  • Dijkstra AJ, Hermann F, Keck W. Cloning and controlled overexpression of the gene encoding the 35 kDa soluble lytic transglycosylase from Escherichia coli. FEBS Lett. 1995 Jun 12;366(2-3):115–118. [PubMed]
  • Dijkstra AJ, Keck W. Identification of new members of the lytic transglycosylase family in Haemophilus influenzae and Escherichia coli. Microb Drug Resist. 1996 Spring;2(1):141–145. [PubMed]
  • Don RH, Cox PT, Wainwright BJ, Baker K, Mattick JS. 'Touchdown' PCR to circumvent spurious priming during gene amplification. Nucleic Acids Res. 1991 Jul 25;19(14):4008–4008. [PMC free article] [PubMed]
  • Doyle RJ, Koch AL. The functions of autolysins in the growth and division of Bacillus subtilis. Crit Rev Microbiol. 1987;15(2):169–222. [PubMed]
  • Ehlert K, Höltje JV, Templin MF. Cloning and expression of a murein hydrolase lipoprotein from Escherichia coli. Mol Microbiol. 1995 May;16(4):761–768. [PubMed]
  • Engel H, Smink AJ, van Wijngaarden L, Keck W. Murein-metabolizing enzymes from Escherichia coli: existence of a second lytic transglycosylase. J Bacteriol. 1992 Oct;174(20):6394–6403. [PMC free article] [PubMed]
  • Glauner B. Separation and quantification of muropeptides with high-performance liquid chromatography. Anal Biochem. 1988 Aug 1;172(2):451–464. [PubMed]
  • Glauner B, Höltje JV. Growth pattern of the murein sacculus of Escherichia coli. J Biol Chem. 1990 Nov 5;265(31):18988–18996. [PubMed]
  • Glauner B, Höltje JV, Schwarz U. The composition of the murein of Escherichia coli. J Biol Chem. 1988 Jul 25;263(21):10088–10095. [PubMed]
  • Goodell EW. Recycling of murein by Escherichia coli. J Bacteriol. 1985 Jul;163(1):305–310. [PMC free article] [PubMed]
  • Goodell EW, Schwarz U. Release of cell wall peptides into culture medium by exponentially growing Escherichia coli. J Bacteriol. 1985 Apr;162(1):391–397. [PMC free article] [PubMed]
  • Hanahan D. Studies on transformation of Escherichia coli with plasmids. J Mol Biol. 1983 Jun 5;166(4):557–580. [PubMed]
  • Höltje JV. From growth to autolysis: the murein hydrolases in Escherichia coli. Arch Microbiol. 1995 Oct;164(4):243–254. [PubMed]
  • Höltje JV. A hypothetical holoenzyme involved in the replication of the murein sacculus of Escherichia coli. Microbiology. 1996 Aug;142(Pt 8):1911–1918. [PubMed]
  • Höltje JV, Mirelman D, Sharon N, Schwarz U. Novel type of murein transglycosylase in Escherichia coli. J Bacteriol. 1975 Dec;124(3):1067–1076. [PMC free article] [PubMed]
  • Hussain M, Ichihara S, Mizushima S. Accumulation of glyceride-containing precursor of the outer membrane lipoprotein in the cytoplasmic membrane of Escherichia coli treated with globomycin. J Biol Chem. 1980 Apr 25;255(8):3707–3712. [PubMed]
  • Ishidate K, Creeger ES, Zrike J, Deb S, Glauner B, MacAlister TJ, Rothfield LI. Isolation of differentiated membrane domains from Escherichia coli and Salmonella typhimurium, including a fraction containing attachment sites between the inner and outer membranes and the murein skeleton of the cell envelope. J Biol Chem. 1986 Jan 5;261(1):428–443. [PubMed]
  • Jacobs C, Huang LJ, Bartowsky E, Normark S, Park JT. Bacterial cell wall recycling provides cytosolic muropeptides as effectors for beta-lactamase induction. EMBO J. 1994 Oct 3;13(19):4684–4694. [PubMed]
  • Janson H, Hedén LO, Forsgren A. Protein D, the immunoglobulin D-binding protein of Haemophilus influenzae, is a lipoprotein. Infect Immun. 1992 Apr;60(4):1336–1342. [PMC free article] [PubMed]
  • Jolliffe LK, Doyle RJ, Streips UN. The energized membrane and cellular autolysis in Bacillus subtilis. Cell. 1981 Sep;25(3):753–763. [PubMed]
  • Kitano K, Tomasz A. Triggering of autolytic cell wall degradation in Escherichia coli by beta-lactam antibiotics. Antimicrob Agents Chemother. 1979 Dec;16(6):838–848. [PMC free article] [PubMed]
  • Koch AL, Doyle RJ. Inside-to-outside growth and turnover of the wall of gram-positive rods. J Theor Biol. 1985 Nov 7;117(1):137–157. [PubMed]
  • 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. [PubMed]
  • Kohlrausch U, Höltje JV. Analysis of murein and murein precursors during antibiotic-induced lysis of Escherichia coli. J Bacteriol. 1991 Jun;173(11):3425–3431. [PMC free article] [PubMed]
  • Koonin EV, Rudd KE. A conserved domain in putative bacterial and bacteriophage transglycosylases. Trends Biochem Sci. 1994 Mar;19(3):106–107. [PubMed]
  • Kulakauskas S, Wikström PM, Berg DE. Efficient introduction of cloned mutant alleles into the Escherichia coli chromosome. J Bacteriol. 1991 Apr;173(8):2633–2638. [PMC free article] [PubMed]
  • Kusser W, Schwarz U. Escherichia coli murein transglycosylase. Purification by affinity chromatography and interaction with polynucleotides. Eur J Biochem. 1980 Jan;103(2):277–281. [PubMed]
  • Lugtenberg B, Meijers J, Peters R, van der Hoek P, van Alphen L. Electrophoretic resolution of the "major outer membrane protein" of Escherichia coli K12 into four bands. FEBS Lett. 1975 Oct 15;58(1):254–258. [PubMed]
  • Park JT. Turnover and recycling of the murein sacculus in oligopeptide permease-negative strains of Escherichia coli: indirect evidence for an alternative permease system and for a monolayered sacculus. J Bacteriol. 1993 Jan;175(1):7–11. [PMC free article] [PubMed]
  • Romeis T, Höltje JV. Specific interaction of penicillin-binding proteins 3 and 7/8 with soluble lytic transglycosylase in Escherichia coli. J Biol Chem. 1994 Aug 26;269(34):21603–21607. [PubMed]
  • Romeis T, Vollmer W, Höltje JV. Characterization of three different lytic transglycosylases in Escherichia coli. FEMS Microbiol Lett. 1993 Aug 1;111(2-3):141–146. [PubMed]
  • Saiki RK, Gelfand DH, Stoffel S, Scharf SJ, Higuchi R, Horn GT, Mullis KB, Erlich HA. Primer-directed enzymatic amplification of DNA with a thermostable DNA polymerase. Science. 1988 Jan 29;239(4839):487–491. [PubMed]
  • Sanger F, Nicklen S, Coulson AR. DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci U S A. 1977 Dec;74(12):5463–5467. [PubMed]
  • Schwarz U, Asmus A, Frank H. Autolytic enzymes and cell division of Escherichia coli. J Mol Biol. 1969 May 14;41(3):419–429. [PubMed]
  • Spratt BG. Properties of the penicillin-binding proteins of Escherichia coli K12,. Eur J Biochem. 1977 Jan;72(2):341–352. [PubMed]
  • Templin MF, Edwards DH, Höltje JV. A murein hydrolase is the specific target of bulgecin in Escherichia coli. J Biol Chem. 1992 Oct 5;267(28):20039–20043. [PubMed]
  • Towbin H, Staehelin T, Gordon J. Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. Proc Natl Acad Sci U S A. 1979 Sep;76(9):4350–4354. [PubMed]
  • Uhlin BE, Clark AJ. Overproduction of the Escherichia coli recA protein without stimulation of its proteolytic activity. J Bacteriol. 1981 Oct;148(1):386–390. [PMC free article] [PubMed]
  • Ursinus A, Höltje JV. Purification and properties of a membrane-bound lytic transglycosylase from Escherichia coli. J Bacteriol. 1994 Jan;176(2):338–343. [PMC free article] [PubMed]
  • Walderich B, Höltje JV. Subcellular distribution of the soluble lytic transglycosylase in Escherichia coli. J Bacteriol. 1991 Sep;173(18):5668–5676. [PMC free article] [PubMed]

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