* To whom correspondence should be addressed.
Received September 18, 2012; Revision received November 2, 2012
This review describes available data on the structure of viral RNA-dependent RNA polymerases (RdRP) obtained from X-ray analysis and discusses the functional significance of the structural elements of these enzymes. Because most of the studies done to date relate to RdRP structures of picorna-, flavi-, and caliciviruses, here we consider mostly the structures of RdRP of these groups of viruses, and also include information about polymerases of other virus families.
KEY WORDS: RNA-dependent RNA polymerase, viral proteins, picornaviruses, polymerase structure