Human DNA Polymerase  : A Novel DNA Polymerase of Unknown Biological Function Encoded by the DINB1 Gene

Recent years have witnessed the discovery of a largenumber of prokaryotic and eukaryotic genes that havebeen predicted or shown to encode novel DNA polymerases (for recent reviews, see Friedberg and Gerlach1999; Woodgate 1999; Friedberg et al. 2000; Goodmanand Tippin 2000). The products of a number of thesegenes are members of the UmuC/DinB nucleotidyl transferase superfamily of DNA polymerases. Others belongto the DNA polymerase families A, B, or X (Friedberg etal. 2000). The precise biological function(s) of many ofthese enzymes is uncertain. Much of this uncertainty derives from the fact that genetic and biological informationthat can be directly correlated with biochemical information is presently limited to a minority of cases. This limitation is problematic because the biochemical characterization of these DNA polymerases utilizes highlyreductionist in vitro systems in which some of the biochemical endpoints measured are highly dependent onprecise experimental conditions (see later discussion)...