Abstract
psr has been reported by M. Ligozzi, F. Pittaluga, and R. Fontana, (J. Bacteriol. 175:2046-2051, 1993) to be a genetic element located just upstream of the structural gene for the low-affinity penicillin-binding protein 5 (PBP 5) in the chromosome of Enterococcus hirae ATCC 9790 and to be involved in the repression of PBP 5 synthesis. By comparing properties of strains of E. hirae that contain a full-length, functional psr with those of strains that possess a truncated form of the gene, we have obtained data that indicate that psr is involved in the regulation of several additional surface-related properties. We observed that cells of strains that possessed a truncated psr were more sensitive to lysozyme-catalyzed protoplast formation, autolyzed more rapidly in 10 mM sodium phosphate (pH 6.8), and, in contrast to strains that possess a functional psr, retained these characteristics after the cultures entered the stationary growth phase. Cellular lytic properties did not correlate with differences in the cellular contents of muramidase-1 or muramidase-2, with the levels of PBP 5 produced, or with the penicillin susceptibilities of the strains. However, a strong correlation was observed with the amounts of rhamnose present in the cell walls of the various strains. All of the strains examined that possessed a truncated form of psr also possessed approximately one-half of the rhamnose content present in the walls of strains that possessed a functional psr. These data suggest that psr is also involved in the regulation of the synthesis of, or covalent linkage to the cell wall peptidoglycan of, a rhamnose-rich polysaccharide. These differences in cell wall composition could be responsible for the observed phenotypic differences. However, the multiple effects of psr suggest that it is part of a global regulatory system that, perhaps independently, affects several cell surface-related properties.
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Selected References
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- Canepari P., Lleò M. M., Cornaglia G., Fontana R., Satta G. In Streptococcus faecium penicillin-binding protein 5 alone is sufficient for growth at sub-maximal but not at maximal rate. J Gen Microbiol. 1986 Mar;132(3):625–631. doi: 10.1099/00221287-132-3-625. [DOI] [PubMed] [Google Scholar]
- Chu C. P., Kariyama R., Daneo-Moore L., Shockman G. D. Cloning and sequence analysis of the muramidase-2 gene from Enterococcus hirae. J Bacteriol. 1992 Mar;174(5):1619–1625. doi: 10.1128/jb.174.5.1619-1625.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cornett J. B., Redman B. E., Shockman G. D. Autolytic defective mutant of Streptococcus faecalis. J Bacteriol. 1978 Feb;133(2):631–640. doi: 10.1128/jb.133.2.631-640.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Coyette J., Ghuysen J. M., Fontana R. The penicillin-binding proteins in Streptococcus faecalis ATCC 9790. Eur J Biochem. 1980 Sep;110(2):445–456. doi: 10.1111/j.1432-1033.1980.tb04886.x. [DOI] [PubMed] [Google Scholar]
- Ellwood D. C., Tempest D. W. Control of teichoic acid and teichuronic acid biosyntheses in chemostat cultures of Bacillus subtilis var. niger. Biochem J. 1969 Jan;111(1):1–5. doi: 10.1042/bj1110001. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fontana R., Cerini R., Longoni P., Grossato A., Canepari P. Identification of a streptococcal penicillin-binding protein that reacts very slowly with penicillin. J Bacteriol. 1983 Sep;155(3):1343–1350. doi: 10.1128/jb.155.3.1343-1350.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fontana R., Grossato A., Rossi L., Cheng Y. R., Satta G. Transition from resistance to hypersusceptibility to beta-lactam antibiotics associated with loss of a low-affinity penicillin-binding protein in a Streptococcus faecium mutant highly resistant to penicillin. Antimicrob Agents Chemother. 1985 Nov;28(5):678–683. doi: 10.1128/aac.28.5.678. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kariyama R., Massidda O., Daneo-Moore L., Shockman G. D. Properties of cell wall-associated DD-carboxypeptidase of Enterococcus hirae (Streptococcus faecium) ATCC 9790 extracted with alkali. J Bacteriol. 1990 Jul;172(7):3718–3724. doi: 10.1128/jb.172.7.3718-3724.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kariyama R., Shockman G. D. Extracellular and cellular distribution of muramidase-2 and muramidase-1 of Enterococcus hirae ATCC 9790. J Bacteriol. 1992 May;174(10):3236–3241. doi: 10.1128/jb.174.10.3236-3241.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kawamura T., Shockman G. D. Purification and some properties of the endogenous, autolytic N-acetylmuramoylhydrolase of Streptococcus faecium, a bacterial glycoenzyme. J Biol Chem. 1983 Aug 10;258(15):9514–9521. [PubMed] [Google Scholar]
- Klare I., Rodloff A. C., Wagner J., Witte W., Hakenbeck R. Overproduction of a penicillin-binding protein is not the only mechanism of penicillin resistance in Enterococcus faecium. Antimicrob Agents Chemother. 1992 Apr;36(4):783–787. doi: 10.1128/aac.36.4.783. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lazarevic V., Margot P., Soldo B., Karamata D. Sequencing and analysis of the Bacillus subtilis lytRABC divergon: a regulatory unit encompassing the structural genes of the N-acetylmuramoyl-L-alanine amidase and its modifier. J Gen Microbiol. 1992 Sep;138(9):1949–1961. doi: 10.1099/00221287-138-9-1949. [DOI] [PubMed] [Google Scholar]
- Ligozzi M., Pittaluga F., Fontana R. Identification of a genetic element (psr) which negatively controls expression of Enterococcus hirae penicillin-binding protein 5. J Bacteriol. 1993 Apr;175(7):2046–2051. doi: 10.1128/jb.175.7.2046-2051.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lleó M. M., Canepari P., Cornaglia G., Fontana R., Satta G. Bacteriostatic and bactericidal activities of beta-lactams against Streptococcus (Enterococcus) faecium are associated with saturation of different penicillin-binding proteins. Antimicrob Agents Chemother. 1987 Oct;31(10):1618–1626. doi: 10.1128/aac.31.10.1618. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SHOCKMAN G. D. Bacterial cell wall synthesis: the effect of threonine depletion. J Biol Chem. 1959 Sep;234:2340–2342. [PubMed] [Google Scholar]
- SHOCKMAN G. D., KOLB J. J., TOENNIES G. Relations between bacterial cell wall synthesis, growth phase, and autolysis. J Biol Chem. 1958 Feb;230(2):961–977. [PubMed] [Google Scholar]
- Sayare M., Daneo-Moore L., Shockman G. D. Influence of macromolecular biosynthesis on cellular autolysis in Streptococcus faecalis. J Bacteriol. 1972 Oct;112(1):337–344. doi: 10.1128/jb.112.1.337-344.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shockman G. D., Conover M. J., Kolb J. J., Phillips P. M., Riley L. S., Toennies G. LYSIS OF STREPTOCOCCUS FAECALIS. J Bacteriol. 1961 Jan;81(1):36–43. doi: 10.1128/jb.81.1.36-43.1961. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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. doi: 10.1073/pnas.76.9.4350. [DOI] [PMC free article] [PubMed] [Google Scholar]
- el Kharroubi A., Jacques P., Piras G., Van Beeumen J., Coyette J., Ghuysen J. M. The Enterococcus hirae R40 penicillin-binding protein 5 and the methicillin-resistant Staphylococcus aureus penicillin-binding protein 2' are similar. Biochem J. 1991 Dec 1;280(Pt 2):463–469. [PMC free article] [PubMed] [Google Scholar]