ABSTRACT
Nucleotide excision repair (NER) in prokaryotes was first discovered in 1964 (1,2) and is one of the most extensively studied DNA repair systems. One key question concerning NER, nicely outlined by Hanawalt and Haynes (3), is: How can one repair complex work on such a wide range of DNA lesions with different chemical properties and conformational properties? While the past 30 years has shed much light on this damage recognition problem, a clear picture of how this protein machine measures the DNA helix to find lesions has remained elusively in the shadows. Over the past 15 years several outstanding reviews have appeared and the reader is encouraged to revisit them (4-7). This chapter will primarily discuss the overall structures of the three principal bacterial proteins involved, UvrA, UvrB, and UvrC, which mediate damage recognition and processing during NER.
