9410239 Etzkorn University of Virginia A covalent tether designed to bend DNA will be used to study the natural target sequence for catabolite activating protein (CAP) when it is bent. The crystal structure of CAP bound to DNA has been solved permitting the design of a structural mimic of the bent DNA. The length of DNA being bent and the amount of bending will be varied in a controlled fashion in order to study a variety of DNA conformations. Unwinding of DNA will be effected by varying the position of attachment of the tether to the phosphate backbone and the biochemical effects will be determined. A possible application is to use stable pieces of bent DNA to target proteins which recognize bent DNA in order to block transcription by RNA polymerase. This grant from the Chemistry Division supports the research of Professor Felicia A. Etzkorn at the University of Virginia in the form of a Research Planning Grant. A mimic of bent DNA will be synthesized and characterized both structurally and functionally. The bending of DNA will be effected by a tether that will be attached at widely spaced positions on the backbone of DNA. The research has possible implications in blocking the formation of RNA, which is dictated by DNA.