Sulfolobus acidocaldarius UDG Can Remove dU from the RNA Backbone: Insight into the Specific Recognition of Uracil Linked with Deoxyribose.

摘要: Sulfolobus acidocaldarius encodes family 4 and 5 uracil-DNA glycosylase (UDG). Two recombinant S. UDGs (SacUDG) were prepared biochemically characterized using oligonucleotides carrying a deaminated base. Both SacUDGs can remove deoxyuracil (dU) base from both double-stranded DNA single-stranded DNA. Interestingly, they U linked with deoxyribose RNA backbone, suggesting that the riboses on backbone have less effect recognition of dU hydrolysis C-N glycosidic bond. However, removal rU is inefficient, strong steric hindrance comes 2' hydroxyl ribose to uracil. cannot 2,2'-anhydro uridine, hypoxanthine, 7-deazaxanthine Compared 2 MUG, other an extra N-terminal structure consisting about 50 residues. Removal 46 residues SacUDG resulted in only 40% decrease activity, indicating [4Fe-4S] cluster truncated secondary are not key elements hydrolyzing Combining our biochemical structural results those groups, we discussed UDGs' catalytic mechanism possible repair reactions bases prokaryotes.