1. Wang, A.H. J. et al. Molecular structure of a left-handed double helical DNA fragmentat atomic resolution.Nature 282, 680–686 (1979).

2. Pohl, F.M. & Jovin, T. M. Salt-induced co-operative conformational change of asynthetic DNA: equilibrium and kinetic studies with poly(dG-dC). J. Mol. Biol.67,375–396 (1972).

3. Thamann,T. J., Lord, R. C., Wang, A. H. J. & Rich, A. High salt form of poly(dG-dC)•poly(dG-dC) is left handed Z-DNA: raman spectra ofcrystals and solutions. Nucl.Acids Res. 9, 5443–5457 (1981).

4. Behe, M.& Felsenfeld, G. Effects of methylation on a synthetic polynucleotide: theB–Z transition in poly(dG–m5dC)•poly(dG–m5dC).Proc. Natl Acad. Sci.USA 78, 1619–1623 (1981).

5. Rich, A.,Nordheim, A. & Wang, A. H.-J. The chemistry and biology of left-handedZ-DNA. Ann. Rev. Biochem.53, 791–846 (1984).

6. Nordheim,A. & Rich, A. The sequence(dC–dA)n•(dG–dT)nforms left-handed Z-DNA in negatively supercoiled plasmids. Proc. Natl Acad.Sci.USA 80, 1821–1825 (1983).

7. Haniford,D. B. & Pulleyblank, D. E. Facile transition of poly[d(TG) x d(CA)] into aleft-handed helix in physiological conditions. Nature 302, 632–634 (1983).

8. Feigon,J., Wang, A. H.-J., van der Marel, G. A., van Boom, J. H. & Rich, A. Z-DNAforms without an alternating purine–pyrimidine sequence in solution. Science230, 82–84 (1985).

9. Peck, L.J., Nordheim, A., Rich, A. & Wang, J. C.Flipping of cloned d(pGpG)n•d(pCpG)n DNA sequences from right to left-handed helicalstructure by salt, Co(III),or negative supercoiling. Proc. Natl Acad. Sci. USA79,4560–4564 (1982).

10. Haniford,D. B. & Pulleyblank, D. E. The in vivo occurrence of Z-DNA. J. Biomol.Struct. Dyn. 1, 593–609 (1983).

11. Ellison,M. J., Kelleher, R. J., Wang, A. H.-J., Habener, J. F.& Rich, A.Sequence-dependent energetics of the B–Z transition in supercoiled DNAcontaining nonalternating purine–pyrimidine sequences. Proc. Natl Acad. Sci.USA 82, 8320–8324 (1985).

12. Ho, P.S., Ellison, M. J., Quigley, G. J. & Rich, A. A computer aidedthermodynamic approach for predicting the formation of Z-DNA in naturallyoccurring sequences. EMBO J. 5, 2737–2744 (1986).

13. Marx, J.Z-DNA: still searching for a function. Science 230, 794–796 (1985).

14. Lafer, E.M., Moller, A., Nordheim, A., Stollar, B. D. & Rich, A. Antibodies specificfor left-handed DNA. Proc.Natl Acad. Sci. USA 78, 3546–3550 (1981).

15. Moller,A. et al. Monoclonal antibodies recognize different parts of Z-DNA. J. Biol.Chem. 257, 12081–12085 (1982).

16. Lafer, E.M. et al. Z-DNA specific antibodies in human systemic lupus erythematosus. J.Clin. Invest. 71,314–321 (1983).

17. Nordheim,A. et al. Antibodies to left-handed Z-DNA bind to interband regions ofDrosophila polytene chromosomes. Nature 294, 417–422 (1981).

18.Lancillotti, F., Lopez, M. C., Arias, P. & Alonso, C. Z-DNA intranscriptionally active chromosomes. Proc. Natl Acad. Sci. USA 84, 1560–1564(1987).

19.Arndt-Jovin, D. J. et al. Left-handed Z-DNA in bands of acid-fixed polytenechromosomes. Proc. Natl Acad. Sci.USA 80, 4344–4348 (1983).

20. Lipps, H.J. et al. Antibodies against Z-DNA react with the macronucleus but not themicronucleus of the hypotrichous ciliate Stylonychia mytilus. Cell 32, 435–441(1983).

21. Liu, L.F. & Wang, J. C. Supercoiling of the DNA template during transcription.Proc. Natl Acad. Sci. USA 84,7024–7027 (1987).

22. Schroth,G. P., Chou, P.-J. & Ho, P. S. Mapping Z-DNA in the human genome: computeraided mapping reveals a non-random distribution of potential Z-DNA forming sequencesin human genes. J. Biol. Chem. 267,11846–11855 (1992).

23. Jackson,D. A., Yuan, J. & Cook, P. R. A gentle method for preparing cyto- andnucleo-skeletons and associated chromatin. J. Cell Sci. 90, 365–378(1988).

24. Wittig,B., Dorbic, T. & Rich, A. The level of Z-DNA in metabolically active,permeabilized mammalian cell nuclei is regulated by torsional strain. J. Cell.Biol. 108,755–764 (1989).

25. Wittig,B., Dorbic, T. & Rich, A. Transcription is associated with Z-DNA formationin metabolically active permeabilized mammalian cell nuclei. Proc. NatlAcad.Sci. USA 88, 2259–2263 (1991).

26. Wittig,B., Wolfl, S., Dorbic, T., Vahrson, W. & Rich, A.Transcription of humanC-MYC in permeabilized nuclei is associated with formation of Z-DNA in three discreteregions of the gene. EMBO J. 11, 4653–4663(1992).

27. Wolfl,S., Wittig, B. & Rich, A. Identification of transcriptionally induced Z-DNAsegments in the human C-MYC gene. Biochim. Biophys. Acta 1264, 294–302(1995).

28. Wolfl,S., Martinez, C., Rich, A. & Majzoub, J. A.Transcription of the humancorticotropin-releasing hormone gene in NPLC cells is correlated with Z-DNA formation.Proc. Natl Acad. Sci. USA 93, 3664–3668(1996).

29. Liu, R.et al. Regulation of CSF1 promoter by the SWI/SNF-like BAF complex. Cell 106,309–318 (2001).

30. Garner,M. M. & Felsenfeld, G. Effect of Z-DNA on nucleosome placement. J. Mol.Biol. 196, 581–590(1987).

31. Herbert,A. G. & Rich, A. A method to identify and characterize Z-DNA bindingproteins using a linear oligodeoxynucleotide. Nucl. Acids Res. 21,2669–2672(1993).

32. Herbert,A., Lowenhaupt, K., Spitzner, J. & Rich, A. Chicken double-stranded RNAadenosine deaminase has apparent specificity for Z-DNA. Proc. Natl Acad.Sci.USA 92, 7550–7554 (1995).

33. Bass, B.L. RNA editing by adenosine deaminases that act on RNA. Annu. Rev. Biochem. 71,817–846(2002).

34. Herbert,A. et al. A Z-DNA binding domain present in the human editing enzyme,double-stranded RNA adenosine deaminase. Proc. Natl Acad. Sci. USA 94,8421–8426(1997).

35. Kim,Y.-G., Kim, P. S., Herbert, A. & Rich, A. Construction of a Z-DNA-specificrestriction endonuclease. Proc. Natl Acad. Sci. USA 94,12875–12879 (1997).

36. Kim, Y.G., Lowenhaupt, K., Schwartz, T. & Rich, A. The interaction between Z-DNAand the Zab domain of dsRNA adenosine deaminase characterized using fusionnucleases. J. Biol. Chem. 274, 19081–19086(1999).

37. Berger,I. et al. Spectroscopic characterization of a DNAbinding domain, Zα, from the editing enzyme dsRNA adenosine deaminase: evidence forleft-handed Z-DNA in the Zα-DNA complex. Biochemistry 37,13313–13321(1998).

38. Kim,Y.-G. et al. The Zab domain of the human RNA editing enzyme ADAR1 recognizesZ-DNA when surrounded by B-DNA. J. Biol. Chem. 275, 26828–26833(2000).

39. Oh,D.-B., Kim, Y.-G. & Rich, A. Z-DNA-binding proteins can act as potenteffectors of gene expression in vivo.Proc. Natl Acad. Sci. USA 99, 16666–16671(2002).

40. Schwartz,T., Rould, M. A., Lowenhaupt, K., Herbert, A. & Rich, A. Crystal structureof the Zα domain of the human editing enzyme ADAR1bound to left-handed Z-DNA. Science 284, 1841–1845 (1999).

41. Herbert,A. & Rich, A. Role of binding domains for dsRNA and Z-DNA in the in vivo editingof minimal substrates by ADAR1. Proc. Natl Acad. Sci. USA 98,12132–12137(2001).

42. Fu, Y. etal. Cloning of DLM-1, a novel gene that is upregulated in activatedmacrophages, using RNA differential display. Gene 240, 157–163 (1999).

43. Schwartz,T., Behlke, J., Lowenhaupt, K., Heinemann,U. & Rich, A. Structure of theDLM-1–Z-DNA complex reveals a conserved family of Z-DNA-binding proteins.NatureStruct. Biol. 8, 761–765 (2001).

44. Brandt,T. A. & Jacobs, B. L. Both carboxy- and aminoterminal domains of thevaccinia virus interferon resistance gene, E3L are required for pathogenesis ina mouse model. J. Virol. 75, 850–856 (2001).

45. Kim,Y.-G. et al. A role for Z-DNA binding in vaccinia virus pathogenesis. Proc.Natl Acad. Sci. USA 100,6974–6979 (2003).

46. Zhang,S., Lockshin, C., Herbert, A., Winter, E. & Rich, A. Zuotin, a putativeZ-DNA binding protein in Saccharomyces cerevisiae. EMBO J. 11, 3787–3796(1992).

47. Zhang,S., Holmes, T., Lockshin, C. & Rich, A. Spontaneous assembly of a self-complementaryoligopeptide to form a stable macroscopic membrane. Proc. Natl Acad. Sci. USA90, 3334–3338(1993).

48. Zhang, S.et al. Self-complementary oligopeptide matrices support mammalian cellattachment. Biomaterials 16, 1385–1393 (1995).

49. Holmes,T., Delacalle, S., Su, X., Rich, A. & Zhang, S. Extensive neurite outgrowthand active neuronal synapses on peptide scaffolds. Proc. Natl Acad. Sci.USA 97,6728–6733 (2000).

50. Kisiday,J. et al. Self-assembling peptide hydrogel fosters chondrocyte extracellularmatrix production and cell division: implications for cartilage tissue repair.Proc. Natl Acad. Sci. USA 99, 9996–10001 (2002).

51. Zhang, S.& Rich, A. Direct conversion of an oligopeptide from a β-sheet to an α-helix: a model for amyloid formation.Proc. Natl Acad. Sci. USA 94, 23–28 (1997).

52. Zhang, S.et al. Biological surface engineering: a simple system for cell patternformation. Biomaterials 20,1213–1220 (1999).

53. Vauthey,S., Santoso, S., Gong, H., Watson, N. &Zhang, S. Molecular self-assembly ofsurfactant-like peptides to form nanotubes and nanovesicles. Proc. Natl Acad.Sci. USA 99, 5355–5360 (2002).

54. vonMaltzahn, G., Vauthey, S., Santoso, S. & Zhang, S.Positively chargedsurfactant-like peptides selfassemble

into nanostructures.Langmuir 19,4332–4337 (2003).

55. Zhang, S.Building from bottom-up. Materials Today 6,20–27 (2003).

56. Uesugi,W., Shida, T. & Ikehara, M. Synthesis and properties of CpG analoguescontaining an 8-bromoguanosine residue. Evidence for Z-RNA duplex formation.Biochemistry 21, 3400–3408 (1982).

57. Hall, K.,Cruz, P., Tinoko, I., Jovin, T. M. &van de Sande, J. H. ‘Z-RNA’ — aleft-handed RNA double helix. Nature 311, 584–586 (1984).

58. Davis, P.W., Hall, K., Cruz, P., Tinoco, I. & Neilson, T. The tetraribonucleotiderCpGpCpG forms a left-handed Z-RNA double helix. Nucleic Acids Res. 14,1279–1291(1986).

59. Teng, M.K., Liaw, Y. C., van der Marel, G. A., van Boom,J. H. & Wang, A.-H. Effectsof the O2’ hydroxyl group on Z-DNA conformation: structure of Z-RNA and(araC)-[Z-DNA]. Biochemistry 28, 4923–4928 (1989).

60. Davis, P.W., Adamiak, R. W. & Tinoco, I. Z-RNA: the solution NMR structure ofr(CGCGCG). Biopolymers 29,109–122 (1990).

61. Hardin,C. C., Zarling, D. A., Wolk, S. K., Ross, W. S. & Tincoc, I.Characterization of anti-Z-RNA polyclonal antibodies: epitope properties andrecognition of Z-DNA. Biochemistry 27, 4169–4177 (1988).

62. Zarling,D. A., Calhoun, C. J., Hardin, C. C. & Zarling, A. H. Cytoplasmic Z-RNA.Proc. Natl Acad. Sci. USA 84,6117–6121 (1987).

63. Zarling,D. A., Calhoun, C. J., Feuerstein, B. G. &

Sena, E. P.Cytoplasmic microinjection of immunoglobulin Gs recognizing RNA helicesinhibits

human cellgrowth. J. Mol. Biol. 211, 147–160 (1990).