251
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Höltje JV, Tomasz A. Purification of the pneumococcal N-acetylmuramyl-L-alanine amidase to biochemical homogeneity. J Biol Chem 1976; 251:4199-207. [PMID: 6472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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252
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Seto H, Tomasz A. Calcium-requiring step in the uptake of deoxyribonucleic acid molecules through the surface of competent pneumococci. J Bacteriol 1976; 126:1113-8. [PMID: 7544 PMCID: PMC233133 DOI: 10.1128/jb.126.3.1113-1118.1976] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The conversion of surface-adsorbed deoxyribonucleic acid (DNA) molecules to a state in which they are inaccessible to exogenous deoxyribonuclease requires specifically calcium ions; magnesium ions cannot replace calcium ions. Virtually maximal levels of nuclease-resistant DNA binding and genetic transformation can be obtained in media free from magnesium and containing only calcium ions. It is suggested that the calcium-requiring process is the transport of DNA molecules across the plasma membrane. Magnesium ions stimulate both the loss of surface-adsorbed DNA to the medium and the extracellular degradation of DNA.
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253
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Cleveland RF, Holtje JV, Wicken AJ, Tomasz A, Daneo-Moore L, Shockman GD. Inhibition of bacterial wall lysins by lipoteichoic acids and related compounds. Biochem Biophys Res Commun 1975; 67:1128-35. [PMID: 1027 DOI: 10.1016/0006-291x(75)90791-3] [Citation(s) in RCA: 127] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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254
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Abstract
Pneumococcal lipoteichoic acid (Forssman antigen) added to the medium of growing pneumococcal cultures caused chain formation, prevented culture lysis in the stationary phase of growth, and inhibited lysis by penicillin and by the pneumococcal bacteriophage Dp-1.
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255
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Seto H, Tomasz A. Selective release of a deoxyribonucleic acid-binding factor from the surface of competent pneumococci. J Bacteriol 1975; 124:969-76. [PMID: 241746 PMCID: PMC235987 DOI: 10.1128/jb.124.2.969-976.1975] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Methods are described that resulted in the selective release of deoxyribonucleic acid (DNA)-binding factor from the surface of competent pneumococci. The same methods caused a parallel inactivation of the DNA-binding capacity of the extracted bacteria. Genetically or physiologically incompetent pneumococci did not yield binding factor upon exposure to the same methods. The solubilized binding factor appeared to be a protein; it could be assayed by a membrane filter binding procedure. The binding factor had properties reminiscent of those of the DNA receptors of transformable pneumococci (Seto et al., 1975).
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256
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Tomasz A, Waks S. Mechanism of action of penicillin: triggering of the pneumococcal autolytic enzyme by inhibitors of cell wall synthesis. Proc Natl Acad Sci U S A 1975; 72:4162-6. [PMID: 674 PMCID: PMC433160 DOI: 10.1073/pnas.72.10.4162] [Citation(s) in RCA: 160] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
During penicillin treatment of an autolysin defective mutant pneumococcus we have observed three novel phenomena: (i) Growth of the mutant cultures is inhibited by the same concentrations of penicillin that induce lysis in the wild type. (ii) Mutant bacteria treated with the minimum growth inhibitory concentration of penicillin will lyse upon the addition of wild-type autolysin to the growth medium. Chloramphenicol and other inhibitors of protein synthesis protect the cells against lysis by exogenous enzyme. Sensitivity of the cells to exogenous autolysin requires treatment with penicillin or other inhibitors of cell wall synthesis (e.g., D-cycloserine or fosfonomycin) since exogenous autolysin alone has no effect on bacterial growth. (iii) Treatment with penicillin (or other inhibitors of cell wall synthesis) causes the escape into the medium of a choline-containing macromolecule that has properties suggesting that it contains pneumococcal lipoteichoic acid (Forssman antigen). Each one of these three phenomena (growth inhibition, sensitization to exogenous autolysin, and leakage of lipoteichoic acid) shows the same dose response as that of the penicillin-induced lysis of wild-type pneumococci. On the basis of these findings we propose a new hypothesis for the mechanism of penicillin-induced lysis of bacteria. It is suggested that inhibition of cell wall synthesis by any means triggers bacterial autolytic enzymes by destabilizing the endogenous complex of an autolysin inhibitor (lipoteichoic acid) and autolytic enzyme. Escape of lipoteichoic acid-like material to the growth medium is a consequence of this labilization. Chloramphenicol protects bacteria against penicillin-induced lysis by interfering with the activity of the autolytic enzyme, rather than by depleting the concentration of the enzyme at the cell surface.
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257
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Tomasz A, Waks S. Enzyme replacement in a bacterium: phenotypic correction by the experimental introduction of the wild type enzyme into a live enzyme defective mutant pneumococcus. Biochem Biophys Res Commun 1975; 65:1311-9. [PMID: 28126 DOI: 10.1016/s0006-291x(75)80373-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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258
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Höltje JV, Tomasz A. Specific recognition of choline residues in the cell wall teichoic acid by the N-acetylmuramyl-L-alanine amidase of Pneumococcus. J Biol Chem 1975; 250:6072-6. [PMID: 238995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Pneumococci growing on choline-containing medium are known to incorporate this amino alcohol into the wall teichoic acid and produce autolysin-sensitive cell walls. In contrast, bacteria grown on the choline analogue, ethanolamine, incorporate ethanolamine into the teichoic acid and synthesize cell walls that are resistant to the homologous autolysin. In this communication, we report experiments aimed at understanding the biochemical mechanism of this phenomenon. Ethanolamine-containing (autolysin-resistant) cell walls were methylated in vitro with methyl iodide. Under appropriate conditions, virtually all of the ethanolamine residues could be converted to choline. After methylation, the formerly autolysin-resistant walls could be quantitatively hydrolyzed by the pneumococcal autolysin. Methylated walls also recovered another property typical of cell walls isolated from choline-grown bacteria: they could induce the in vitro "conversion" of an inactive form of autolysin to the catalytically active form (Tomasz, A., and Westphal, M. (1971) Proc. Natl. Acad. Sci. U.S.A. 68, 2627-2630). The results suggest that the autolysin-catalyzed hydrolysis of amide bonds in the peptidoglycan requires an additional interaction between the enzyme protein and choline residues in the teichoric acid portion of the cell wall.
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259
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Seto H, Lopez R, Tomasz A. Cell surface-located deoxyribonucleic acid receptors in transformable pneumococci. J Bacteriol 1975; 122:1339-50. [PMID: 238945 PMCID: PMC246191 DOI: 10.1128/jb.122.3.1339-1350.1975] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
We studied deoxyribonucleic acid (DNA) binding in transformable pneumococci. The relevant findings are as follows. (i) At least half of the DNA Molecules adsorbed to competent cells in the growth medium are attached to sites on the protoplast membrane. (ii) Most of the DNA bound to live competent cells in the presence of glucose is not released by moderate shear or by autolysin treatment. In contrast, most of the DNA adsorbed to competent cells in the absence of glucose is shear and autolysin sensitive. (iii) The presence of binding sites resembling in properties the sites in live competent cells can be demonstrated in wall-membrane complexes. Most of these sites are lost during preparation of cell walls and protoplasts. It is suggested that the DNA-binding site is a membrane component (protein?) Stabilized by polysaccharide (cell Wall) material. (IV) Mechanical or enzymatic damage to the cell wall or change in the ionic conditions can induce DNA binding (and surface-nuclease activity) in the incompetent pneumococci. However, such cells still show neither genetic transformation nor extensive nuclease-resistant binding of DNA. It is suggested that both competent and incompetent cells contain a large number of sequestered DNA-binding sites that can be unmasked by several experimental conditions. Induction of the competent state by the competence activator protein may involve an endogenous unmasking process.
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260
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Seto H, Lopez R, Garrigan O, Tomasz A. Nucleolytic degradation of homologous and heterologous deoxyribonucleic acid molecules at the surface of competent pneumococci. J Bacteriol 1975; 122:676-85. [PMID: 236283 PMCID: PMC246106 DOI: 10.1128/jb.122.2.676-685.1975] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Competent pneumococci can catalyze the rapid and quantitative degradation of extracellular deocyribonucleic acid (DNA) molecules through the activity of surface-located nucleases (endo- and, possibly, exonucleases as well). Both homologous and heterologous DNAs are degraded by a mechanism that seems to involve a cyclic process: (i) attachment of DNA to the cell surface followed by (ii) nucleolytic attack, and (iii) release to the medium. Processes (ii) and (iii) are both inhibited by ethylenediaminetetraacetate. Whereas surface nuclease activity is specific for competent cells, the bulk of this activity is not coupled to irreversible DNA uptake (deoxyribonuclease-resistant binding). Pneumococcal DNA treated with ultraviolet irradiation or nitrous acid (cross-linking?) is selectively impaired in the ability to irreversibly bind to competent cells, whereas reversible binding is normal.
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261
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Höltje JV, Tomasz A. Lipoteichoic acid: a specific inhibitor of autolysin activity in Pneumococcus. Proc Natl Acad Sci U S A 1975; 72:1690-4. [PMID: 239401 PMCID: PMC432610 DOI: 10.1073/pnas.72.5.1690] [Citation(s) in RCA: 164] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The choline-containing pneumococcal lipoteichoic acid (Forssman antigen) is a powerful inhibitor of the homologous autolytic enzyme, an N-acetylmuramyl-L-alanine amidase (EC 3.5.1.28, MUCOPEPTIDE AMIDOHYDROLASE). Low concentrations of deoxycholate can reverse the inhibition. Wall teichoic acid preparations are inactive at several hundred-fold higher concentrations. Activation of an inactive form of autolysin by in vitro incubation with choline-containing cell walls is also inhibited by lipoteichoic acid. Addition of lipoteichoic acid to the growth medium of pneumococcal cultures causes chain formation, resistance to stationary phase lysis, and penicillin tolerance. It is suggested that a physiological role of lipoteichoic acids may be in the in vivo control of autolysin activity.
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262
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Briles EB, Tomasz A. Membrane lipoteichoic acid is not a precursor to wall teichoic acid in pneumococci. J Bacteriol 1975; 122:335-7. [PMID: 235510 PMCID: PMC235676 DOI: 10.1128/jb.122.1.335-337.1975] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The distribution of a pulse of teichoic acid-specific radiolabel between wall and membrane teichoic acids in pneumococci was constant over a subsequent chase period, suggesting that wall and membrane teichoic acids are biosynthesized simultaneously and independently.
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263
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264
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Briles EB, Tomasz A. Physiological studies on the pneumococcal Forssman antigen: a choline-containing lipoteichoic acid. JOURNAL OF GENERAL MICROBIOLOGY 1975; 86:267-74. [PMID: 234510 DOI: 10.1099/00221287-86-2-267] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The cell concentration and possible biological activities of the pneumococcal Forssman (F) antigen (membrane lipoteichoic acid) were examined in a number of physiological situations. In test tube cultures of pneumococci the concentration of the Forssman antigen per bacterium showed no significant fluctuations within a typical culture cycle. Purified F antigen had no effect on the activation of pneumococci to competence for genetic transformation, DNA mediated genetic transformation or adsorption of the pneumococcal phage Dp-1 to bacteria. Pneumococci grown in the presence of different amino alcohols (ethanolamine, N-monomethylethanolamine, or choline) exhibit differences with regard to both their ability to stimulate heterophile (haemolytic) antibody production in rabbits and in their ability to bind such antibodies. Choline-grown bacteria seem to cross-react with sheep red blood cells better than do the analogue-grown bacteria.
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265
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Tomasz A, McDonnell M, Westphal M, Zanati E. Coordinated incorporation of nascent peptidoglycan and teichoic acid into pneumococcal cell walls and conservation of peptidoglycan during growth. J Biol Chem 1975; 250:337-41. [PMID: 237892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Choline-containing pneumococcal cell wals are sensitive to autolysin, whereas ethanolamine-containing walls are not. Bacteria were labeled with radioactive peptidoglycan precursors while growing either in choline- or in ethanolaminecontaining media. Subsequently, the labeled cells were allowed to grow for four to five generations in nonradioactive medium supplemented with the alternative amino alcohol source (i.e. cells labeled in choline medium yields ethanolamine; cells labeled in ethanolamine medium yields choline). The autolysin sensitivity of the isotope label in cell walls prepared from such bacteria indicates that nascent peptidoglycan and teichoic acid units that are synthesized at the same time are attached to one another, incorporated into the cell surface at the cellular equator, and remain conserved during growth the division of the bacteria.
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266
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Tomasz A, Westphal M, Briles EB, Fletcher P. On the physiological functions of teichoic acids. JOURNAL OF SUPRAMOLECULAR STRUCTURE 1975; 3:1-16. [PMID: 239275 DOI: 10.1002/jss.400030102] [Citation(s) in RCA: 45] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The choline-containing teichoic acids of pneumococci can be modified by biosynthetic replacement of the choline residues with certain structural analogues, such as ethanolamine (EA) or the N-monomethyl-(MEA) and N-dimethyl-(DEA) amino derivatives of ethanolamine. Cells containing such analogues in their teichoic acids develop pleiomorphic alterations in several physiological properties, which include resistance to detergent-induced lysis and inhibition of cell separation (chain formation). We report here the results of physiological studies on the mechanism of these two phenomena. Our results are summarized in the following: (a) Pneumococci grown on various amino alcohols produce cell walls of identical amino sugar and amino acid composition. (b) Both choline- and EA-containing teichoic acids seem to follow the same conservative pattern of segregation during growth and cell division.(c)Lysis sensitivity of pneumococci requires the juxtaposition oflysissensitive (choline-containing) cell walls and endogenous autolysin at the cell wall growth zone. (d) Upon readdition of choline to ethanolamine-containing cells, lysis sensitivity and catalytically active (C-type) autolysin reappear in the bacteria with the same kinetics. (e) The chains of EA-grown pneumococci contain fully compartmentalized cells and normal cross walls.
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267
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Tomasz A, McDonnell M, Westphal M, Zanati E. Coordinated incorporation of nascent peptidoglycan and teichoic acid into pneumococcal cell walls and conservation of peptidoglycan during growth. J Biol Chem 1975. [DOI: 10.1016/s0021-9258(19)42020-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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268
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Seto H, Tomasz A. Protoplast formation and leakage of intramembrane cell components: induction by the competence activator substance of pneumococci. J Bacteriol 1975; 121:344-53. [PMID: 234940 PMCID: PMC285649 DOI: 10.1128/jb.121.1.344-353.1975] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Treatment of pneumococci with activator (a protein that induces bacterial "competence" to absorb deoxyribonucleic acid molecules and undergo genetic transformation) can cause either protoplast formation or leakage of intracellular components to the medium depending on postincubation conditions. The leaked intracellular components include nucleoside phosphates, beta-galactosidase, deoxyribonuclease, autolysin, and hemolysin. Leakage and protoplast formation are induced by the electrophoretically pure activator, and these phenomena require the same conditions as induction of competence for genetic transformation, namely, genetic capacity for competence, protein synthesis, incorporation of choline, and the optimal pH for activation. It is suggested that the activator protein accelerates a normal process of transport (leakage) of autolysin molecules into the periplasmic space. The activity of these autolysin molecules from within would then unmask deoxyribonucleic acid binding sites located on the plasma membrane.
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269
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Höltje JV, Tomasz A. Teichoic acid phosphorylcholine esterase. A novel enzyme activity in pneumococcus. J Biol Chem 1974; 249:7032-4. [PMID: 4153792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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270
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271
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Seto H, Tomasz A. Early stages in DNA binding and uptake during genetic transformation of pneumococci. Proc Natl Acad Sci U S A 1974; 71:1493-8. [PMID: 4151520 PMCID: PMC388256 DOI: 10.1073/pnas.71.4.1493] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Ethylenediaminetetraacetate and other divalent-cation-complexing agents greatly stimulate the cellular binding of DNA molecules to competent pneumococci, while the appearance of genetic transformants and nuclease-resistant DNA binding are completely inhibited. Based on this finding, we developed an experimental system in which three early and consecutive stages of genetic transformation can be experimentally separated: (i) attachment of DNA molecules to cell surface sites that are only demonstrable in the competent state; (ii) a divalent-cation-dependent nucleolytic splitting and release of the adsorbed molecules to the medium; and (iii) emergence of potential transformants accompanied by an energy-requiring and divalent-cation-dependent process in which the cell-associated DNA molecules become inaccessible to shearing forces, nucleases, anti-DNA serum, and polycations.
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272
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Briles EB, Tomasz A. Pneumococcal Forssman antigen. A choline-containing lipoteichoic acid. J Biol Chem 1973; 248:6394-7. [PMID: 4147161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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273
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Abstract
Three classes of 5-fluorpyrimidine-resistant mutants of Diplococcus pneumoniae have been characterized. The mutant strain upp is resistant to high concentrations of the fluoropyrimidine bases fluorouracil (FU) and fluorocytosine (FC); strain upp has a defective uridine monophosphate pyrophosphorylase. The mutant strain udk is resistant to inhibition by fluorouridine (FUR) and exhibits defective uridine kinase activity. The mutant strain fun is resistant to inhibition by the nucleosides fluorodeoxyuridine, fluorodeoxycytidine, and FUR, but shows normal activity for all pyrimidine pathway enzymes tested. This strain may be defective in the activity of a transport system that governs the cellular uptake of pyrimidine ribo- and deoxyribonucleosides. Biochemical studies on wild-type and fluoropyrimidine-resistant pneumococci are discussed with respect to the transport and early metabolism of preformed pyrimidine precursors by this organism.
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274
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Bean B, Tomasz A. Selective utilization of pyrimidine deoxyribonucleosides for deoxyribonucleic acid synthesis in pneumococcus. J Bacteriol 1973; 113:1356-62. [PMID: 4144169 PMCID: PMC251705 DOI: 10.1128/jb.113.3.1356-1362.1973] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
When pyrimidine deoxyribonucleosides are supplied to growing cultures of Diplococcus pneumoniae, they are selectively used for incorporation into deoxyribonucleic acid (DNA). Differently labeled molecules of deoxyuridine, thymidine, and deoxycytidine were used to study the precursor pathways of this organism. Each of these preformed pyrimidine deoxynucleosides is incorporated intact (i.e., without cleavage of the glycosidic bond) and is predominantly recoverable as DNA thymidine. During the utilization of deoxycytidine and deoxyuridine by pneumococci, large proportions of the available precursor are converted to free thymidine, which is secreted back into the growth medium. The biochemical pathways for selective incorporation into DNA and the regulation of concentrations of intracellular thymidine compounds by excretion of free thymidine are discussed.
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276
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Tomasz A, Westphal M. Abnormal autolytic enzyme in a pneumococus with altered teichoic acid composition. Proc Natl Acad Sci U S A 1971; 68:2627-30. [PMID: 4399413 PMCID: PMC389487 DOI: 10.1073/pnas.68.11.2627] [Citation(s) in RCA: 86] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Pneumococci in which the choline component of the cell wall teichoic acid was replaced by ethanolamine contain an abnormal autolytic enzyme that has a low molecular weight and low activity in contrast to the enzyme typical of choline-containing bacteria that has a high molecular weight and high activity. The abnormal autolysin can be converted to the normal (cholinetype) enzyme by incubation in vitro with choline-containing cell walls.
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277
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Tomasz A, Zanati E, Ziegler R. DNA uptake during genetic transformation and the growing zone of the cell envelope. Proc Natl Acad Sci U S A 1971; 68:1848-52. [PMID: 4399665 PMCID: PMC389306 DOI: 10.1073/pnas.68.8.1848] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Continuous cellular incorporation of choline molecules is essential for DNA binding to competent pneumococci. The choline molecules are incorporated into the cell surface at the equatorial region of the cocci. As a working hypothesis, it is proposed that DNA molecules enter these bacteria at the growing zone(s) of the cell envelope.
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278
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Bean B, Tomasz A. Inhibitory effects and metabolism of 5-fluoropyrimidine derivatives in pneumococcus. J Bacteriol 1971; 106:412-20. [PMID: 4396791 PMCID: PMC285111 DOI: 10.1128/jb.106.2.412-420.1971] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
5-Fluorouracil (FU), 5-fluorocytosine, and the riboside and deoxyriboside derivatives of these fluoropyrimidines each exhibit a different spectrum of inhibitory effects in pneumococci. The biochemical basis of this finding seems to be the extremely low level of nucleoside phosphorylase (hydrolase) and N-trans-deoxyribosylase activity in pneumococcus and the consequent, relatively limited metabolic interconversion of the different fluoropyrimidines, which can therefore selectively affect one or the other of the several drug-sensitive biochemical reactions in this bacterium. Special attention was paid to the effect of fluoropyrimidines on the metabolism of cytosine and thymidine. In spite of the fact that FU is converted to both fluorouridine triphosphate and fluorocytidine triphosphate, only fluorouridylate but no fluorocytidylate can be detected in the ribonucleic acid Exogenous FU and fluorouridine also inhibit the synthesis of cytosine nucleotides from supplied uridine in a pyrimidine auxotroph. Thymidine was found to be a poor reversing agent for any of the fluoropyrimidine inhibitions. In both the wild type and in a thymidine-requiring (thymidylate-synthetase deficient) mutant, growing with supplied thymidine in the medium, fluorodeoxyuridine (FUdR) treatment caused cell death and inhibition of the incorporation of radioactive thymidine, adenosine, or uracil into deoxyribonucleic acid. It is suggested that FUdR (or a metabolic derivative) inhibits the transport of phosphorylation of thymidine in this microorganism.
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279
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Tomasz A, Zanati E. ppearance of a protein "agglutinin" on the spheroplast membrane of pneumococci during induction of competence. J Bacteriol 1971; 105:1213-5. [PMID: 4396142 PMCID: PMC248564 DOI: 10.1128/jb.105.3.1213-1215.1971] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Competent pneumococci and their spheroplasts agglutinate in dilute acid. Agglutination is caused by a trypsin-sensitive agglutinin which is not identical to the competence factor and the appearance of which requires protein synthesis.
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280
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Ziegler R, Tomasz A. Binding of the competence factor to receptors in the spheroplast membrane of pneumococci. Biochem Biophys Res Commun 1970; 41:1342-9. [PMID: 4394905 DOI: 10.1016/0006-291x(70)90236-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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281
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Briles EB, Tomasz A. Radioautographic evidence for equatorial wall growth in a gram-positive bacterium. Segregation of choline-3H-labeled teichoic acid. J Cell Biol 1970; 47:786-90. [PMID: 4395735 PMCID: PMC2108156 DOI: 10.1083/jcb.47.3.786] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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282
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Tomasz A, Albino A, Zanati E. Multiple antibiotic resistance in a bacterium with suppressed autolytic system. Nature 1970; 227:138-40. [PMID: 4393335 DOI: 10.1038/227138a0] [Citation(s) in RCA: 327] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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283
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Tomasz A. Cellular metabolism in genetic transformation of pneumococci: requirement for protein synthesis during induction of competence. J Bacteriol 1970; 101:860-71. [PMID: 4392399 PMCID: PMC250403 DOI: 10.1128/jb.101.3.860-871.1970] [Citation(s) in RCA: 106] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Metabolic inhibitors have differential effects on various phases of genetic transformation in pneumococci. Evidence is presented suggesting that, in addition to the competence factor, another specific protein or class of proteins is essential for the development of cellular "competence." The precise role of this protein(s) in genetic transformation is not known, but it seems essential for some function subsequent to the interaction of competence factor and cells.
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Mosser JL, Tomasz A. Choline-containing teichoic acid as a structural component of pneumococcal cell wall and its role in sensitivity to lysis by an autolytic enzyme. J Biol Chem 1970; 245:287-98. [PMID: 4391619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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Tomasz A. Biological consequences of the replacement of choline by ethanolamine in the cell wall of Pneumococcus: chanin formation, loss of transformability, and loss of autolysis. Proc Natl Acad Sci U S A 1968; 59:86-93. [PMID: 4385544 PMCID: PMC286006 DOI: 10.1073/pnas.59.1.86] [Citation(s) in RCA: 151] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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Abstract
Radioactive choline is incorporated by pneumococcus (strain R36A) into a polymeric substance from which it can be quantitatively recovered as free choline, after hydrolysis by strong acid. The polymeric substance is insoluble in lipid solvents and can be degraded by periodate. Fractionation studies and chemical analyses suggest that choline is linked to a polysaccharide component of pneumococcal cell wall.
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Tomasz A. Model for the mechanism controlling the expression of competent state in Pneumococcus cultures. J Bacteriol 1966; 91:1050-61. [PMID: 4379672 PMCID: PMC315996 DOI: 10.1128/jb.91.3.1050-1061.1966] [Citation(s) in RCA: 99] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Tomasz, Alexander (The Rockefeller University, New York, N.Y.). Model for the mechanism controlling the expression of competent state in pneumococcus cultures. J. Bacteriol. 91:1050-1061. 1966.-The phenotypic expression of competence allowing the cells to absorb genetically active deoxyribonucleic acid molecules from their environment was examined in pneumococcal cultures growing under a variety of environmental conditions. The most important single parameter affecting the time course of this expression process was found to be the cell concentration. Constant high levels of competence could be maintained in cultures growing in a continuous-dilution device. The expression of competence seems to occur through a specific induction process "catalyzed" by a macromolecular cell product-the activator substance. Under most growth conditions, the availability of endogenous activator seems to limit the expression of competence. An "autocatalytic" production of activator ensues during the activation of cells to the competent state. Evidence is presented for physiological influences affecting the cell's capacity to react with the activator. A physiological model is proposed for the control of the competent state in pneumococcus.
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Tomasz A, Mosser JL. On the nature of the pneumococcal activator substance. Proc Natl Acad Sci U S A 1966; 55:58-66. [PMID: 4380138 PMCID: PMC285755 DOI: 10.1073/pnas.55.1.58] [Citation(s) in RCA: 108] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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Tomasz A, Beiser SM. Relationship between the competence antigen and the competence-activator substance in pneumococci. J Bacteriol 1965; 90:1226-32. [PMID: 4379003 PMCID: PMC315806 DOI: 10.1128/jb.90.5.1226-1232.1965] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Tomasz, Alexander (The Rockefeller Institute, New York, N.Y.), and Samuel M. Beiser. Relationship between the competence antigen and the competence-activator substance in pneumococci. J. Bacteriol. 90:1226-1232. 1965.-Antisera prepared against pneumococci in their competent phase inhibit deoxyribonuoleic acid (DNA)-mediated genetic transformation as well as binding of radioactive DNA by the cells. The same sera do not inhibit transformation of competent Haemophilus influenzae and Bacillus subtilis cells, but transformation of a Streptococcus strain genetically related to pneumococci is inhibited. The kinetics of immune inhibition of transformation resembles the inactivation of bacteriophage by phage-neutralizing antisera. The appearance of the competence antigen on the surface of pneumococci can be induced by the competence-activator substance. Antisera prepared against competent pneumococci can also inhibit the conversion of incompetent cells to competence by the competence-activator substance. The possibility is considered that part of the new antigenic determinant appearing on the cell surface during competence may be the activator itself.
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Tomasz A. Control of the competent state in Pneumococcus by a hormone-like cell product: an example for a new type of regulatory mechanism in bacteria. Nature 1965; 208:155-9. [PMID: 5884251 DOI: 10.1038/208155a0] [Citation(s) in RCA: 138] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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