西亚试剂：Ku is a 5′-dRP/AP lyase that excises nucleotide damage near

发布时间：2025-09-19

Ku is a 5′-dRP/AP lyase that excises nucleotide damage near broken ends
Steven A. Roberts1, Natasha Strande1, Martin D. Burkhalter1, Christina Strom1, Jody M. Havener1, Paul Hasty2 & Dale A. Ramsden1

1 Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, and Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
2 Department of Molecular Medicine and Institute of Biotechnology, The University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, San Antonio, Texas 78245, USA

Top of pageMammalian cells require non-homologous end joining (NHEJ) for the efficient repair of chromosomal DNA double-strand breaks1. A key feature of biological sources of strand breaks is associated nucleotide damage, including base loss (abasic or apurinic/apyrimidinic (AP) sites)2. At single-strand breaks, 5′-terminal abasic sites are excised by the 5′-deoxyribose-5-phosphate (5′-dRP) lyase activity of DNA polymerase?β (pol?β)3, 4, 5, 6: here we show, in vitro and in cells, that accurate and efficient repair by NHEJ of double-strand breaks with such damage similarly requires 5′-dRP/AP lyase activity. Classically defined NHEJ is moreover uniquely effective at coupling this end-cleaning step to joining in cells, helping to distinguish this pathway from otherwise robust alternative NHEJ pathways. The NHEJ factor Ku can be identified as an effective 5′-dRP/AP lyase. In a similar manner to other lyases7, Ku nicks DNA 3′ of an abasic site by a mechanism involving a Schiff-base covalent intermediate with the abasic site. We show by using cell extracts that Ku is essential for the efficient removal of AP sites near double-strand breaks and, consistent with this result, that joining of such breaks is specifically decreased in cells complemented with a lyase-attenuated Ku mutant. Ku had previously been presumed only to recognize ends and recruit other factors that process ends; our data support an unexpected direct role for Ku in end-processing steps as well.

• 以上资料由西亚试剂：http://www.xiyashiji.com/ 提供此产品的详细信息如密度,含量,分子式,分子量等均可在西亚官网查询   
• 相关产品如溴化汞硝酸亚汞氯化亚汞乙酸苯汞氯化钾汞 碘化汞钾硫氰酸汞硫酸亚汞氧化汞氯化汞碘化汞硝酸汞三氯氧磷三氯化磷碘甲烷二碘甲烷三碘甲烷三氟碘甲烷氘代碘甲烷碘乙烷1,2-二碘乙烷甲酸铷碘化铷溴化铷铬酸铷硫酸铷氟化铷硝酸铷氯化铷碳酸铷硫酸镱 碳酸镱氯化镱硝酸镱氧化镱等均有销售.欢迎订购

上一篇：西亚试剂：氯化乙酰甲胆碱
下一篇：对氟苯甲酰氯生产方法