This book contains the papers which were presented at the First Gulf Shores Symposium on Unusual DNA Structures. The meeting was held April 6-8, 1987, in Gulf Shores, Alabama. Averitable explosion has taken place in recent years regarding our understanding of unusual DNA structures. This symposium was dedicated to enhancing our understanding of the biology and chemistry of these important structural features. The symposium was supported by funds provided by the Department of Biochemistry, University of Alabama at Birmingham, Schools of Medicine and Dentistry. We wish to express our app eciationto Ms. Patti Guyton for her expert organizational skills and assistance in organizing the meeting and preparation of this book. Robert D. Wells and Stephen C. Harvey Department of Biochemistry Schools of Medicine and Dentistry University of Alabama at Birmingham Birmingham, Alabama 35294 VII VIII;;C' Pete Dickie 1. Dave Wilson 20. 39. Paul Hagerman 58. Robert Shapiro 2. Wang-Ting Hsieh David Pettijohn 21. 40. Jacquelynn Larson 59. Angel Garcia 3. Hark Glover Hicaela Caserta 22. 41. Johanna Griffin 60. Richard Lavery 4. David Pulleyblank 23. Adam Jaworski 42. Jeremy Lee 61. Norma Wills 5. Robert Wells 24. Han Htun 43.