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Excision and repair of mismatched base pairs in transformation of Streptococcus pneumoniae


The use of heteroduplex DNA molecules as donors in pneumococcal transformation makes it possible to follow the fate of each DNA strand. The integration efficiency of each strand depends strongly upon the single base changes it carries. The function (hex) which reduces drastically the transformation yield of markers referred to as low efficiency (LE) tends to remove either donor strand without respect to which one is introduced. In the case of high efficiency (HE) markers the reduction in the transformation yield involves the elimination of only one donor strand. For a given locus it can be either one depending upon the mutation. The reduction in transformation yield can be less drastic for HE markers than for both strands of the LE markers. These data are discussed in terms of differences in the affinity for mismatched base pairs.

We have studied the transfer of information from each donor DNA strand to the recipient genome, on the basis of differences in the rates of phenotypic expression of a given marker introduced on opposite strands. Results show that, as in the case of LE markers, the information from HE markers, when introduced on the strand recognized by the hex function, is transmitted to both strands of the recipient molecule. Correction of the recipient strand to homozygosis probably accounts for this information transfer. These results, together with earlier investigations, strongly suggest that the hex function is an excision-repair system acting on donor-recipient base pair mismatches.

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  1. Balassa, C.: Action de la mitomycine C sur la transformation du pneumocoque. Ann. Inst. Pasteur Lille 102, 547–555 (1962)

  2. Brown, N.C.: Inhibition of bacterial DNA replication by 6-(p-hydroxyphenylazo)-uracil: Differential effect on repair and semi-conservative synthesis in Bacillus subtilis. J. Mol. Biol. 59, 1–16 (1971)

  3. Claverys, J.P., Lefèvre, J.C., Sicard, A.M.: Molecular studies on the marker effect in pneumococcus. In: Transformation 1978 (S.W. Glover and L.O. Butler, eds.). Oxford: Costwold Press Ltd. pp. 135–150 (1979)

  4. Ephrussi-Taylor, H.: Genetic recombination in DNA-induced transformation of pneumococcus. IV. The pattern of transmission and phenotypic expression of high and low efficiency donor sites in the ami-A locus. Genetics 54, 211–222 (1966)

  5. Ephrussi-Taylor, H., Gray, T.C.: Genetic studies of recombining DNA in pneumococcal transformation. J. Gen. Physiol. 49, Part 2, 211–231 (1966)

  6. Ephrussi-Taylor, H., Sicard, A.M., Kamen, R.: Genetic recombination in DNA-induced transformation of pneumococcus. I. The problem of relative efficiency of transforming factors. Genetics 51, 455–475 (1965)

  7. Fox, M.S.: Deoxyribonucleic acid incorporation by transformed bacteria. Biochim. Biophys. Acta 26, 83–85 (1957)

  8. Fox, M.S., Allen, M.K.: On the mechanism of deoxyribonucleate integration in pneumococcal transformation Proc. Natl. Acad. Sci. U.S.A. 52, 412–419 (1964)

  9. Gabor, M., Hotchkiss, R.D.: Manifestation of linear organization in molecules of pneumococcal transforming DNA. Proc. Natl. Acad. Sci. U.S.A. 56, 1441–1448 (1966)

  10. Gabor, M., Hotchkiss, R.D.: Differences in rate of phenotypic expression in separated strands of pneumococcal transforming DNA and evidence for change of reading direction. Genetics sup. 61, 15–25 (1969)

  11. Gasc, A.M., Sicard, A.M.: Mutagénèse induite par l'hydroxylamine sur l'ADN du pneumocoque. C.R. Acad. Sci. Paris 275, 285–287 (1972)

  12. Guild, W.R., Shoemaker, N.B.: Mismatch correction in pneumococcal transformation: Donor Length and hex — dependent marker efficiency. J. Bacteriol. 125, 125–135 (1976)

  13. Green, D.M.: A host-specific variation affecting relative frequency of transformation of two markers in pneumococcus. Exp. Cell Res. 18, 466–480 (1959)

  14. Guild, W.R., Shoemaker, N.B.: Intracellular competition for a mismatch recognition system and marker specific rescue of transforming DNA from inactivation by ultraviolet irradiation. Mol. Gen. Genet. 128, 291–300 (1974)

  15. Hotchkiss, R.D.: Isolation of sodium deoxyribonucleate in biologically active form from bacteria. Methods in Enzymology, Vol. 3, pp. 692–696 (1957)

  16. Hotchkiss, R.D.: Models of genetic recombination. Annu. Rev. Microbiol. 28, 445–468 (1974)

  17. Lacks, S.: Molecular fate of DNA in genetic transformation. J. Mol. Biol. 5, 119–131 (1962)

  18. Lacks, S.: Integration efficiency and genetic recombination in pneumococcal transformation. Genetics 53, 207–235 (1966)

  19. Lacks, S.: Mutants of Diplococcus pneumoniae that lack deoxyribonucleases and other activities possibly pertinent to genetic transformation. J. Bacteriol. 101, 373–383 (1970)

  20. Lefèvre, J.C., Claverys, J.P., Sicard, A.M.: Donor deoxyribonucleic acid length and marker effect in pneumococcal transformation. J. Bacteriol. 138, 80–86 (1979)

  21. Lerman, R.S., Tolmach, L.J.: Genetic transformation. I. Cellular incorporation of DNA accompanying transformation in pneumococcus. Biochim. Biophys. Acta 28, 68–82 (1957)

  22. Louarn, J.M.: Action du rayonnement ultraviolet sur l'intégration des marqueurs génétiques au cours de la transformation chez Diplococcus pneumoniae. C.R. Acad. Sci. Paris 262, 325–328 (1966)

  23. Louarn, J.M.: Etude de la recombinaison génétique chez Diplococcus pneumoniae. Thèse Université de Toulouse, France (1970)

  24. Louarn, J.M., Sicard, A.M.: Transmission of genetic information during transformation in Diplococcus pneumoniae. Biochem. Biophys. Res. Commun. 30, 683–689 (1968)

  25. Louarn, J.M., Sicard, A.M.: Identical transformability of both strands of recipient DNA in Diplococcus pneumoniae. Biochem. Biophys. Res. Commun. 36, 101–109 (1969)

  26. Low, R. L., Rashbaum, S.A., Cozarelli, N.R.: Mechanism of inhibition of Bacillus subtilis DNA polymerase III by the arylhydrazinopyrimidine antimicrobial agents. Proc. Natl. Acad. Sci. U.S.A. 71, 2973–2977 (1974)

  27. Nomura, M., Engbaek, F.: Expression of ribosomal protein genes as analysed by bacteriophage Mu — induced mutations. Proc. Natl. Acad. Sci. U.S.A. 69, 1526–1530 (1972)

  28. Peterson, J.M., Guild, W.R.: Fractionated strands of bacterial deoxyribonucleic acid. III. Transformation efficiencies and rates of phenotypic expression. J. Bacteriol. 96, 1991–1996 (1968)

  29. Radding, C.M.: Genetic recombination: strand transfer and mismatch repair. Annu. Rev. Biochem. 47, 847–880 (1978)

  30. Roger, M.: Evidence for conversion of heteroduplex transforming DNAs to homoduplexes by recipient pneumococcal cells. Proc. Natl. Acad. Sci. U.S.A. 69, 466–470 (1972)

  31. Roger, M.: Mismatch excision and possible polarity effects result in preferred deoxyribonucleic acid strand of integration in pneumococcal transformation. J. Bacteriol. 129, 298–304 (1977)

  32. Shoemaker, N.B., Guild, W.R.: Destruction of low efficiency markers is a slow process occuring at a heteroduplex stage of transformation. Mol. Gen. Genet. 128, 283–290 (1974)

  33. Sicard, A.M.: A new synthetic medium for Diplococcus pneumoniae, and its use for the study of reciprocal transformations at the ami-A locus. Genetics 50, 31–44 (1964)

  34. Sicard, A.M., Ephrussi-Taylor, H.: Genetic recombination in DNA-induced transformation of pneumococcus. II. Mapping the ami-A region. Genetics 52, 1207–1227 (1965)

  35. Sicard, A.M., Ephrussi-Taylor, H.: Recombinaison génétique dans la transformation chez le pneumocoque. Etude des réversions an locus ami-A. C.R. Acad. Sci. Paris. 262, 2305–2308 (1966)

  36. Sirotnak, F.M., Hachtel, S.L.: Increased dihydrofolate reductase synthesis in Diplococcus pneumoniae following translatable alteration of the structural gene. I. Genotype derivation and recombination analyses. Genetics 61, 293–312 (1969)

  37. Suzuki, K., Yamagami, H., Shimazu, Y.: Effect of Mitomycin C on Early Phenotypic Expression in the Transformation of Diplococcus pneumoniae. Nature 20, 929–930 (1965)

  38. Tiraby, G., Fox, M.S.: Marker discrimination in transformation and mutation of pneumococcus. Proc. Natl. Acad. Sci. U.S.A. 70, 3541–3545 (1973)

  39. Tiraby, G., Fox, M.S.: Marker discrimination and mutagen induced alteration in pneumococcal transformation. Genetics 77, 449–458 (1974a)

  40. Tiraby, G., Fox, M.S.: On the mechanism of the hex function in mutation and transformation of pneumococcus. In: Proceedings of the Gatlinburg meeting in mechanisms in recombination (R. Grell, ed.), pp. 225–236. New York and London: Plenum Press 1974b

  41. Tiraby, G., Fox, M.S., Bernheimer, H.: Marker discrimination in DNA-induced transformation of various pneumococcus strains. J. Bacteriol. 70, 3535–3541 (1975)

  42. Tiraby, G., Sicard, A.M.: Integration efficiencies of spontaneous mutant alleles of ami-A locus in pneumococcal transformation J. Bacteriol. 116, 1130–1135 (1973)

  43. Tye, B.K., Lehman, I.R.: Excision repair of uracil incorporated in DNA as a result of a defect in d UTPase. J. Mol. Biol. 117, 293–306 (1977)

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Correspondence to J. P. Claverys.

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Communicated by K. Isono

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Claverys, J.P., Roger, M. & Sicard, A.M. Excision and repair of mismatched base pairs in transformation of Streptococcus pneumoniae . Molec. Gen. Genet. 178, 191–201 (1980).

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  • Streptococcus Pneumoniae
  • Base Change
  • Information Transfer
  • Phenotypic Expression
  • Single Base