Leiros Ingar, Moe Elin, Smalås Arne O, McSweeney Sean
The European Synchrotron Radiation Facility, 38043 Grenoble CEDEX 9, France.
Acta Crystallogr D Biol Crystallogr. 2005 Aug;61(Pt 8):1049-56. doi: 10.1107/S090744490501382X. Epub 2005 Jul 20.
Uracil-DNA glycosylases are DNA-repair enzymes that catalyse the removal of promutagenic uracil from single- and double-stranded DNA, thereby initiating the base-excision repair (BER) pathway. Uracil in DNA can occur by mis-incorporation of dUMP in place of dTMP during DNA synthesis or by deamination of cytosine, resulting in U-A or U-G mispairs. The radiation-resistant bacterium Deinococcus radiodurans has an elevated number of uracil-DNA glycosylases compared with most other organisms. The crystal structure of dr0689 (uracil-DNA N-glycosylase), which has been shown to be the major contributor to the removal of mis-incorporated uracil bases in crude cell extracts of D. radiodurans, is reported.
尿嘧啶-DNA糖基化酶是一类DNA修复酶，可催化从单链和双链DNA中去除具有诱变作用的尿嘧啶，从而启动碱基切除修复（BER）途径。DNA中的尿嘧啶可通过DNA合成过程中dUMP错掺入取代dTMP，或通过胞嘧啶脱氨产生，导致U-A或U-G错配。与大多数其他生物相比，耐辐射细菌耐辐射球菌的尿嘧啶-DNA糖基化酶数量更多。本文报道了dr0689（尿嘧啶-DNA N-糖基化酶）的晶体结构，该酶已被证明是耐辐射球菌粗细胞提取物中去除错掺入尿嘧啶碱基的主要贡献者。
