Chemical etiology of nucleic acid structure: Comparing pentopyranosyl- (2'→4') oligonucleotides with RNA

Science

Volumn 283, Issue 5402, 1999, Pages 699-703

  Beier, M ^a   Reck, F ^a   Wagner, T ^a   Krishnamurthy, R ^a   Eschenmoser, A ^a  

^a NONE

Author keywords

[No Author keywords available]

Indexed keywords

NUCLEIC ACID; OLIGONUCLEOTIDE; PYRANOSIDE; RNA; SUGAR;

ARTICLE; BASE PAIRING; CHEMICAL ANALYSIS; CHEMICAL STRUCTURE; CONFORMATION; NUCLEIC ACID STRUCTURE; PRIORITY JOURNAL; STRUCTURE ANALYSIS; TEMPERATURE DEPENDENCE; THERMODYNAMICS;

ARABINOSE; BASE PAIRING; CIRCULAR DICHROISM; EVOLUTION, MOLECULAR; NUCLEIC ACID CONFORMATION; NUCLEIC ACID DENATURATION; OLIGONUCLEOTIDES; OLIGORIBONUCLEOTIDES; PENTOSES; RIBOSE; RNA; TEMPERATURE; THERMODYNAMICS; XYLOSE;

EID: 0033613846     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.283.5402.699     Document Type: Article

References (53)

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2. A. Eschenmoser, in Verh. Ges. Dtsch. Naturforsch. Aerzte 116, 135 (1990); _ and M. Dobler, Helv. Chim. Acta 75, 218 (1992): A. Eschenmoser and E. Loewenthal, Chem. Soc. Rev. 21, 1 (1992); A. Eschenmoser, in Proc. Robert A. Welch Found. Conf. Chem. Res. 37 (Robert A. Welch Foundation, Houston, TX, 1993), p. 201.
3. A. Eschenmoser, in Verh. Ges. Dtsch. Naturforsch. Aerzte 116, 135 (1990); _ and M. Dobler, Helv. Chim. Acta 75, 218 (1992): A. Eschenmoser and E. Loewenthal, Chem. Soc. Rev. 21, 1 (1992); A. Eschenmoser, in Proc. Robert A. Welch Found. Conf. Chem. Res. 37 (Robert A. Welch Foundation, Houston, TX, 1993), p. 201.
4. A. Eschenmoser, in Verh. Ges. Dtsch. Naturforsch. Aerzte 116, 135 (1990); _ and M. Dobler, Helv. Chim. Acta 75, 218 (1992): A. Eschenmoser and E. Loewenthal, Chem. Soc. Rev. 21, 1 (1992); A. Eschenmoser, in Proc. Robert A. Welch Found. Conf. Chem. Res. 37 (Robert A. Welch Foundation, Houston, TX, 1993), p. 201.
5. The closest structural alternative to RNA that satisfies this criterion is the RNA isomer containing (2′→5′)- instead of the (3′→5′)-phosphodiester junctions. For studies on this system in the etiological context, see L. E. Orgel, J. Mol. Biol. 38, 381 (1968); _ and R. Lohrmann, Acc. Chem. Res. 7, 368 (1974); D. A. Usher, Nature New Biol. 235, 207 (1972); _ and A. H. McHale, Proc. Natl. Acad. Sci. U.S.A. 73, 1149 (1976); R. Kierzek, L. He, D. H. Turner, Nucleic Acids Res. 20, 1685 (1992); T. P. Prakash, C. Roberts, C. Switzer, Angew. Chem. Int. Ed. Engl. 36, 1522 (1997); H. Sawai, J. Seki, H. Ozaki, J. Biomol. Struct. Dyn. 13, 1043 (1996). For studies on the related (2′→5′) DNA isomer, see J. P. Dougherty, C. J. Rizzo, R. Breslow, J. Am. Chem. Soc. 114, 6254 (1992); H. Hashimoto and C. Switzer, ibid., p. 6255; T. P. Prakash, K.-E. Jung, C. Switzer, Chem. Commun. 1793 (1996).
6. The closest structural alternative to RNA that satisfies this criterion is the RNA isomer containing (2′→5′)- instead of the (3′→5′)-phosphodiester junctions. For studies on this system in the etiological context, see L. E. Orgel, J. Mol. Biol. 38, 381 (1968); _ and R. Lohrmann, Acc. Chem. Res. 7, 368 (1974); D. A. Usher, Nature New Biol. 235, 207 (1972); _ and A. H. McHale, Proc. Natl. Acad. Sci. U.S.A. 73, 1149 (1976); R. Kierzek, L. He, D. H. Turner, Nucleic Acids Res. 20, 1685 (1992); T. P. Prakash, C. Roberts, C. Switzer, Angew. Chem. Int. Ed. Engl. 36, 1522 (1997); H. Sawai, J. Seki, H. Ozaki, J. Biomol. Struct. Dyn. 13, 1043 (1996). For studies on the related (2′→5′) DNA isomer, see J. P. Dougherty, C. J. Rizzo, R. Breslow, J. Am. Chem. Soc. 114, 6254 (1992); H. Hashimoto and C. Switzer, ibid., p. 6255; T. P. Prakash, K.-E. Jung, C. Switzer, Chem. Commun. 1793 (1996).
7. The closest structural alternative to RNA that satisfies this criterion is the RNA isomer containing (2′→5′)- instead of the (3′→5′)-phosphodiester junctions. For studies on this system in the etiological context, see L. E. Orgel, J. Mol. Biol. 38, 381 (1968); _ and R. Lohrmann, Acc. Chem. Res. 7, 368 (1974); D. A. Usher, Nature New Biol. 235, 207 (1972); _ and A. H. McHale, Proc. Natl. Acad. Sci. U.S.A. 73, 1149 (1976); R. Kierzek, L. He, D. H. Turner, Nucleic Acids Res. 20, 1685 (1992); T. P. Prakash, C. Roberts, C. Switzer, Angew. Chem. Int. Ed. Engl. 36, 1522 (1997); H. Sawai, J. Seki, H. Ozaki, J. Biomol. Struct. Dyn. 13, 1043 (1996). For studies on the related (2′→5′) DNA isomer, see J. P. Dougherty, C. J. Rizzo, R. Breslow, J. Am. Chem. Soc. 114, 6254 (1992); H. Hashimoto and C. Switzer, ibid., p. 6255; T. P. Prakash, K.-E. Jung, C. Switzer, Chem. Commun. 1793 (1996).
8. The closest structural alternative to RNA that satisfies this criterion is the RNA isomer containing (2′→5′)- instead of the (3′→5′)-phosphodiester junctions. For studies on this system in the etiological context, see L. E. Orgel, J. Mol. Biol. 38, 381 (1968); _ and R. Lohrmann, Acc. Chem. Res. 7, 368 (1974); D. A. Usher, Nature New Biol. 235, 207 (1972); _ and A. H. McHale, Proc. Natl. Acad. Sci. U.S.A. 73, 1149 (1976); R. Kierzek, L. He, D. H. Turner, Nucleic Acids Res. 20, 1685 (1992); T. P. Prakash, C. Roberts, C. Switzer, Angew. Chem. Int. Ed. Engl. 36, 1522 (1997); H. Sawai, J. Seki, H. Ozaki, J. Biomol. Struct. Dyn. 13, 1043 (1996). For studies on the related (2′→5′) DNA isomer, see J. P. Dougherty, C. J. Rizzo, R. Breslow, J. Am. Chem. Soc. 114, 6254 (1992); H. Hashimoto and C. Switzer, ibid., p. 6255; T. P. Prakash, K.-E. Jung, C. Switzer, Chem. Commun. 1793 (1996).
9. The closest structural alternative to RNA that satisfies this criterion is the RNA isomer containing (2′→5′)- instead of the (3′→5′)-phosphodiester junctions. For studies on this system in the etiological context, see L. E. Orgel, J. Mol. Biol. 38, 381 (1968); _ and R. Lohrmann, Acc. Chem. Res. 7, 368 (1974); D. A. Usher, Nature New Biol. 235, 207 (1972); _ and A. H. McHale, Proc. Natl. Acad. Sci. U.S.A. 73, 1149 (1976); R. Kierzek, L. He, D. H. Turner, Nucleic Acids Res. 20, 1685 (1992); T. P. Prakash, C. Roberts, C. Switzer, Angew. Chem. Int. Ed. Engl. 36, 1522 (1997); H. Sawai, J. Seki, H. Ozaki, J. Biomol. Struct. Dyn. 13, 1043 (1996). For studies on the related (2′→5′) DNA isomer, see J. P. Dougherty, C. J. Rizzo, R. Breslow, J. Am. Chem. Soc. 114, 6254 (1992); H. Hashimoto and C. Switzer, ibid., p. 6255; T. P. Prakash, K.-E. Jung, C. Switzer, Chem. Commun. 1793 (1996).
10. The closest structural alternative to RNA that satisfies this criterion is the RNA isomer containing (2′→5′)- instead of the (3′→5′)-phosphodiester junctions. For studies on this system in the etiological context, see L. E. Orgel, J. Mol. Biol. 38, 381 (1968); _ and R. Lohrmann, Acc. Chem. Res. 7, 368 (1974); D. A. Usher, Nature New Biol. 235, 207 (1972); _ and A. H. McHale, Proc. Natl. Acad. Sci. U.S.A. 73, 1149 (1976); R. Kierzek, L. He, D. H. Turner, Nucleic Acids Res. 20, 1685 (1992); T. P. Prakash, C. Roberts, C. Switzer, Angew. Chem. Int. Ed. Engl. 36, 1522 (1997); H. Sawai, J. Seki, H. Ozaki, J. Biomol. Struct. Dyn. 13, 1043 (1996). For studies on the related (2′→5′) DNA isomer, see J. P. Dougherty, C. J. Rizzo, R. Breslow, J. Am. Chem. Soc. 114, 6254 (1992); H. Hashimoto and C. Switzer, ibid., p. 6255; T. P. Prakash, K.-E. Jung, C. Switzer, Chem. Commun. 1793 (1996).
11. The closest structural alternative to RNA that satisfies this criterion is the RNA isomer containing (2′→5′)- instead of the (3′→5′)-phosphodiester junctions. For studies on this system in the etiological context, see L. E. Orgel, J. Mol. Biol. 38, 381 (1968); _ and R. Lohrmann, Acc. Chem. Res. 7, 368 (1974); D. A. Usher, Nature New Biol. 235, 207 (1972); _ and A. H. McHale, Proc. Natl. Acad. Sci. U.S.A. 73, 1149 (1976); R. Kierzek, L. He, D. H. Turner, Nucleic Acids Res. 20, 1685 (1992); T. P. Prakash, C. Roberts, C. Switzer, Angew. Chem. Int. Ed. Engl. 36, 1522 (1997); H. Sawai, J. Seki, H. Ozaki, J. Biomol. Struct. Dyn. 13, 1043 (1996). For studies on the related (2′→5′) DNA isomer, see J. P. Dougherty, C. J. Rizzo, R. Breslow, J. Am. Chem. Soc. 114, 6254 (1992); H. Hashimoto and C. Switzer, ibid., p. 6255; T. P. Prakash, K.-E. Jung, C. Switzer, Chem. Commun. 1793 (1996).
12. The closest structural alternative to RNA that satisfies this criterion is the RNA isomer containing (2′→5′)- instead of the (3′→5′)-phosphodiester junctions. For studies on this system in the etiological context, see L. E. Orgel, J. Mol. Biol. 38, 381 (1968); _ and R. Lohrmann, Acc. Chem. Res. 7, 368 (1974); D. A. Usher, Nature New Biol. 235, 207 (1972); _ and A. H. McHale, Proc. Natl. Acad. Sci. U.S.A. 73, 1149 (1976); R. Kierzek, L. He, D. H. Turner, Nucleic Acids Res. 20, 1685 (1992); T. P. Prakash, C. Roberts, C. Switzer, Angew. Chem. Int. Ed. Engl. 36, 1522 (1997); H. Sawai, J. Seki, H. Ozaki, J. Biomol. Struct. Dyn. 13, 1043 (1996). For studies on the related (2′→5′) DNA isomer, see J. P. Dougherty, C. J. Rizzo, R. Breslow, J. Am. Chem. Soc. 114, 6254 (1992); H. Hashimoto and C. Switzer, ibid., p. 6255; T. P. Prakash, K.-E. Jung, C. Switzer, Chem. Commun. 1793 (1996).
13. The closest structural alternative to RNA that satisfies this criterion is the RNA isomer containing (2′→5′)- instead of the (3′→5′)-phosphodiester junctions. For studies on this system in the etiological context, see L. E. Orgel, J. Mol. Biol. 38, 381 (1968); _ and R. Lohrmann, Acc. Chem. Res. 7, 368 (1974); D. A. Usher, Nature New Biol. 235, 207 (1972); _ and A. H. McHale, Proc. Natl. Acad. Sci. U.S.A. 73, 1149 (1976); R. Kierzek, L. He, D. H. Turner, Nucleic Acids Res. 20, 1685 (1992); T. P. Prakash, C. Roberts, C. Switzer, Angew. Chem. Int. Ed. Engl. 36, 1522 (1997); H. Sawai, J. Seki, H. Ozaki, J. Biomol. Struct. Dyn. 13, 1043 (1996). For studies on the related (2′→5′) DNA isomer, see J. P. Dougherty, C. J. Rizzo, R. Breslow, J. Am. Chem. Soc. 114, 6254 (1992); H. Hashimoto and C. Switzer, ibid., p. 6255; T. P. Prakash, K.-E. Jung, C. Switzer, Chem. Commun. 1793 (1996).
14. The closest structural alternative to RNA that satisfies this criterion is the RNA isomer containing (2′→5′)- instead of the (3′→5′)-phosphodiester junctions. For studies on this system in the etiological context, see L. E. Orgel, J. Mol. Biol. 38, 381 (1968); _ and R. Lohrmann, Acc. Chem. Res. 7, 368 (1974); D. A. Usher, Nature New Biol. 235, 207 (1972); _ and A. H. McHale, Proc. Natl. Acad. Sci. U.S.A. 73, 1149 (1976); R. Kierzek, L. He, D. H. Turner, Nucleic Acids Res. 20, 1685 (1992); T. P. Prakash, C. Roberts, C. Switzer, Angew. Chem. Int. Ed. Engl. 36, 1522 (1997); H. Sawai, J. Seki, H. Ozaki, J. Biomol. Struct. Dyn. 13, 1043 (1996). For studies on the related (2′→5′) DNA isomer, see J. P. Dougherty, C. J. Rizzo, R. Breslow, J. Am. Chem. Soc. 114, 6254 (1992); H. Hashimoto and C. Switzer, ibid., p. 6255; T. P. Prakash, K.-E. Jung, C. Switzer, Chem. Commun. 1793 (1996).
15. A. Eschenmoser, Origins Life Evol. Biosphere 24, 389 (1994).
16. J. Hunziker et al., Helv. Chim. Acta 76, 259 (1993); C. Otting et al., ibid., p. 2701; K. Groebke et al., ibid. 81, 375 (1998).
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19. S. Pitsch, S. Wendeborn, B. Jaun, A. Eschenmoser, ibid. 76, 2161 (1993) (synthesis and pairing properties); S. Pitsch et al., ibid. 78, 1621 (1995) (pairing properties); I. Schlönvogt et al., ibid. 79, 2316 (1996) (NMR structure); R. Krishnamurthy et al., Angew. Chem. Int. Ed. Engl. 35, 1537 (1996) (enantio pairing); R. Micura, M. Bolli, N. Windhab, A. Eschenmoser, ibid. 36, 870 (1997) (hairpin formation); M. Bolli, R. Micura, S. Pitsch, A. Eschenmoser, Helv. Chim. Acta 80, 1901 (1997) (replication); M. Bolli, R. Micura, A. Eschenmoser, Chem. Biol. 4, 309 (1997) (self-templated oligomerization).
20. S. Pitsch, S. Wendeborn, B. Jaun, A. Eschenmoser, ibid. 76, 2161 (1993) (synthesis and pairing properties); S. Pitsch et al., ibid. 78, 1621 (1995) (pairing properties); I. Schlönvogt et al., ibid. 79, 2316 (1996) (NMR structure); R. Krishnamurthy et al., Angew. Chem. Int. Ed. Engl. 35, 1537 (1996) (enantio pairing); R. Micura, M. Bolli, N. Windhab, A. Eschenmoser, ibid. 36, 870 (1997) (hairpin formation); M. Bolli, R. Micura, S. Pitsch, A. Eschenmoser, Helv. Chim. Acta 80, 1901 (1997) (replication); M. Bolli, R. Micura, A. Eschenmoser, Chem. Biol. 4, 309 (1997) (self-templated oligomerization).
21. S. Pitsch, S. Wendeborn, B. Jaun, A. Eschenmoser, ibid. 76, 2161 (1993) (synthesis and pairing properties); S. Pitsch et al., ibid. 78, 1621 (1995) (pairing properties); I. Schlönvogt et al., ibid. 79, 2316 (1996) (NMR structure); R. Krishnamurthy et al., Angew. Chem. Int. Ed. Engl. 35, 1537 (1996) (enantio pairing); R. Micura, M. Bolli, N. Windhab, A. Eschenmoser, ibid. 36, 870 (1997) (hairpin formation); M. Bolli, R. Micura, S. Pitsch, A. Eschenmoser, Helv. Chim. Acta 80, 1901 (1997) (replication); M. Bolli, R. Micura, A. Eschenmoser, Chem. Biol. 4, 309 (1997) (self-templated oligomerization).
22. S. Pitsch, S. Wendeborn, B. Jaun, A. Eschenmoser, ibid. 76, 2161 (1993) (synthesis and pairing properties); S. Pitsch et al., ibid. 78, 1621 (1995) (pairing properties); I. Schlönvogt et al., ibid. 79, 2316 (1996) (NMR structure); R. Krishnamurthy et al., Angew. Chem. Int. Ed. Engl. 35, 1537 (1996) (enantio pairing); R. Micura, M. Bolli, N. Windhab, A. Eschenmoser, ibid. 36, 870 (1997) (hairpin formation); M. Bolli, R. Micura, S. Pitsch, A. Eschenmoser, Helv. Chim. Acta 80, 1901 (1997) (replication); M. Bolli, R. Micura, A. Eschenmoser, Chem. Biol. 4, 309 (1997) (self-templated oligomerization).
23. S. Pitsch, S. Wendeborn, B. Jaun, A. Eschenmoser, ibid. 76, 2161 (1993) (synthesis and pairing properties); S. Pitsch et al., ibid. 78, 1621 (1995) (pairing properties); I. Schlönvogt et al., ibid. 79, 2316 (1996) (NMR structure); R. Krishnamurthy et al., Angew. Chem. Int. Ed. Engl. 35, 1537 (1996) (enantio pairing); R. Micura, M. Bolli, N. Windhab, A. Eschenmoser, ibid. 36, 870 (1997) (hairpin formation); M. Bolli, R. Micura, S. Pitsch, A. Eschenmoser, Helv. Chim. Acta 80, 1901 (1997) (replication); M. Bolli, R. Micura, A. Eschenmoser, Chem. Biol. 4, 309 (1997) (self-templated oligomerization).
24. S. Pitsch, S. Wendeborn, B. Jaun, A. Eschenmoser, ibid. 76, 2161 (1993) (synthesis and pairing properties); S. Pitsch et al., ibid. 78, 1621 (1995) (pairing properties); I. Schlönvogt et al., ibid. 79, 2316 (1996) (NMR structure); R. Krishnamurthy et al., Angew. Chem. Int. Ed. Engl. 35, 1537 (1996) (enantio pairing); R. Micura, M. Bolli, N. Windhab, A. Eschenmoser, ibid. 36, 870 (1997) (hairpin formation); M. Bolli, R. Micura, S. Pitsch, A. Eschenmoser, Helv. Chim. Acta 80, 1901 (1997) (replication); M. Bolli, R. Micura, A. Eschenmoser, Chem. Biol. 4, 309 (1997) (self-templated oligomerization).
25. S. Pitsch, S. Wendeborn, B. Jaun, A. Eschenmoser, ibid. 76, 2161 (1993) (synthesis and pairing properties); S. Pitsch et al., ibid. 78, 1621 (1995) (pairing properties); I. Schlönvogt et al., ibid. 79, 2316 (1996) (NMR structure); R. Krishnamurthy et al., Angew. Chem. Int. Ed. Engl. 35, 1537 (1996) (enantio pairing); R. Micura, M. Bolli, N. Windhab, A. Eschenmoser, ibid. 36, 870 (1997) (hairpin formation); M. Bolli, R. Micura, S. Pitsch, A. Eschenmoser, Helv. Chim. Acta 80, 1901 (1997) (replication); M. Bolli, R. Micura, A. Eschenmoser, Chem. Biol. 4, 309 (1997) (self-templated oligomerization).
26. For pentopyranosyl-mononucleosides prepared for biological testing, see M. Fuertes, J. T. Witkowski, R. K. Robins, J. Org. Chem. 40, 2372 (1975); A. P. Martinez, W. W. Lee, L Goodman, ibid. 34, 92 (1969); A. P. Martinez and W. W. Lee, ibid., p. 416; _, L. Goodman, J. Med. Chem. 12, 1125 (1969). See also B. Doboszewski, N. Blaton, J. Rozenski, A. De Bruyn, P. Herdewijn, Tetrahedron 51, 5381 (1995).
27. For pentopyranosyl-mononucleosides prepared for biological testing, see M. Fuertes, J. T. Witkowski, R. K. Robins, J. Org. Chem. 40, 2372 (1975); A. P. Martinez, W. W. Lee, L Goodman, ibid. 34, 92 (1969); A. P. Martinez and W. W. Lee, ibid., p. 416; _, L. Goodman, J. Med. Chem. 12, 1125 (1969). See also B. Doboszewski, N. Blaton, J. Rozenski, A. De Bruyn, P. Herdewijn, Tetrahedron 51, 5381 (1995).
28. For pentopyranosyl-mononucleosides prepared for biological testing, see M. Fuertes, J. T. Witkowski, R. K. Robins, J. Org. Chem. 40, 2372 (1975); A. P. Martinez, W. W. Lee, L Goodman, ibid. 34, 92 (1969); A. P. Martinez and W. W. Lee, ibid., p. 416; _, L. Goodman, J. Med. Chem. 12, 1125 (1969). See also B. Doboszewski, N. Blaton, J. Rozenski, A. De Bruyn, P. Herdewijn, Tetrahedron 51, 5381 (1995).
29. For pentopyranosyl-mononucleosides prepared for biological testing, see M. Fuertes, J. T. Witkowski, R. K. Robins, J. Org. Chem. 40, 2372 (1975); A. P. Martinez, W. W. Lee, L Goodman, ibid. 34, 92 (1969); A. P. Martinez and W. W. Lee, ibid., p. 416; _, L. Goodman, J. Med. Chem. 12, 1125 (1969). See also B. Doboszewski, N. Blaton, J. Rozenski, A. De Bruyn, P. Herdewijn, Tetrahedron 51, 5381 (1995).
30. For pentopyranosyl-mononucleosides prepared for biological testing, see M. Fuertes, J. T. Witkowski, R. K. Robins, J. Org. Chem. 40, 2372 (1975); A. P. Martinez, W. W. Lee, L Goodman, ibid. 34, 92 (1969); A. P. Martinez and W. W. Lee, ibid., p. 416; _, L. Goodman, J. Med. Chem. 12, 1125 (1969). See also B. Doboszewski, N. Blaton, J. Rozenski, A. De Bruyn, P. Herdewijn, Tetrahedron 51, 5381 (1995).
31. moc group.
32. moc group.
33. moc group.
34. Details concerning preparation of building blocks and automated syntheses of oligomers in the three new pentopyranosyl-(2′→4′) oligonucleotide series will be published in Helv. Chim. Acta [F. Reck, H. Wippo, R. Kudick (L-α-lyxopyranosyl series); M. Beier and O. Jungmann (D- and L-α-arabinopyranosyl series); T. Wagner (D-β-xylopyrsnosyl series); R. Krishnamurthy and A. Eschenmoser, in preparation].
35. 8) are essentially unchanged in the range 10° to 80°C (1.0 M NaCl).
36. 8 strands of the (D)-pr-, (L)-pl-, and (D)-px series with complementary strands of the (D)-r series. For (L)-pr sequences, see (5). β-pr = ribo-, α-pl = lyxo-, β-px = xylo-, and α-pa = arabinopyranosyl; D = 2,6-diaminopurine.
37. R. Micura, R. Kudick, S. Pitsch, A. Eschenmoser, Angew. Chem., in press; see also M. Bolli et al. (5).
38. For such relative duplex stabilities when base pairing is not Watson-Crick but Hoogsteen, see M. Bolli, J. C. Litten, R. Schütz, C. J. Leumann, Chem. Biol. 3, 197 (1996).
39. For recently described strong base-pairing systems of the phosphodiester type, compare with R. Steffens and C. J. Leumann, J. Am. Chem. Soc. 119, 11548 (1997); S. K. Singh, P. Nielsen, A. A. Koshkin, J. Wengel, Chem. Commun., 455 (1998).
40. For recently described strong base-pairing systems of the phosphodiester type, compare with R. Steffens and C. J. Leumann, J. Am. Chem. Soc. 119, 11548 (1997); S. K. Singh, P. Nielsen, A. A. Koshkin, J. Wengel, Chem. Commun., 455 (1998).
41. m = 57°C, 10 μM, 0.15 M NaCl) is being carried out in the laboratory of B. Jaun (ETH).
42. G. F. Joyce and L E. Orgel, in The RNA World, R. F. Gesteland and J. F. Atkins, Eds. (Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY, 1993), p. 1.
43. A chemical phenotype of an informational system involves the whole of sequence-specific (and thus "inheritable") reactivities and catalytic properties apt to act as selection factors in the system's replication. Compare with A. Eschenmoser, Origins Life Evol. Biosphere 27, 535 (1997).
44. D. Müller et al., Helv. Chim. Acta. 73, 1410 (1990); G. Zubay, Origins Life Evol. Biosphere 28, 13 (1998); R. Krishnamurthy, S. Pitsch, G. Arrhenius, ibid., in press.
45. D. Müller et al., Helv. Chim. Acta. 73, 1410 (1990); G. Zubay, Origins Life Evol. Biosphere 28, 13 (1998); R. Krishnamurthy, S. Pitsch, G. Arrhenius, ibid., in press.
46. D. Müller et al., Helv. Chim. Acta. 73, 1410 (1990); G. Zubay, Origins Life Evol. Biosphere 28, 13 (1998); R. Krishnamurthy, S. Pitsch, G. Arrhenius, ibid., in press.
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48. B. Bennua-Skalmowski, K. Krolikiewicz, H. Vorbrüggen, Tetrahedron Lett. 36, 7845 (1995); J. Wengel and C. Scheuer-Larsen, Bioorg. Med. Chem. Lett. 7, 1999 (1997).
49. A. G. Cairns-Smith, Genetic Takeover and the Mineral Origin of Life (Cambridge Univ. Press, Cambridge, 1982); G. F. Joyce, A. W. Schwartz, S. L. Miller, L. E. Orgel, Proc. Natl. Acad. Sci U.S.A. 84, 4398 (1987).
50. A. G. Cairns-Smith, Genetic Takeover and the Mineral Origin of Life (Cambridge Univ. Press, Cambridge, 1982); G. F. Joyce, A. W. Schwartz, S. L. Miller, L. E. Orgel, Proc. Natl. Acad. Sci U.S.A. 84, 4398 (1987).
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52. M. Resmini, thesis, Universität Konstanz, Germany, 1993 (W. Pfleiderer).
53. m determinations, and G. Joyce (La Jolla) for critically reading the manuscript.