Ku is a 5'-dRP/AP lyase that excises nucleotide damage near broken ends

Steven A Roberts; Natasha Strande; Martin D Burkhalter; Christina Strom; Jody M Havener; Paul Hasty; Dale A Ramsden

doi:10.1038/nature08926

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Ku is a 5'-dRP/AP lyase that excises nucleotide damage near broken ends

Journal article

Open access

Peer reviewed

Ku is a 5'-dRP/AP lyase that excises nucleotide damage near broken ends

Steven A Roberts, Natasha Strande, Martin D Burkhalter, Christina Strom, Jody M Havener, Paul Hasty and Dale A Ramsden

Nature (London), Vol.464(7292), pp.1214-1217

04/22/2010

DOI: https://doi.org/10.1038/nature08926

Handle:

https://hdl.handle.net/2376/105665

PMID: 20383123

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Abstract

Cell Line

Biocatalysis

Antigens, Nuclear - metabolism

Humans

DNA-Binding Proteins - genetics

DNA Breaks, Double-Stranded

DNA-Binding Proteins - metabolism

DNA-(Apurinic or Apyrimidinic Site) Lyase - genetics

Animals

Antigens, Nuclear - genetics

DNA-(Apurinic or Apyrimidinic Site) Lyase - metabolism

Ku Autoantigen

DNA Repair

Schiff Bases - chemistry

Fibroblasts

Cell Extracts

Mice

DNA Damage

HeLa Cells

Ribosemonophosphates - metabolism

Mammalian cells require non-homologous end joining (NHEJ) for the efficient repair of chromosomal DNA double-strand breaks. A key feature of biological sources of strand breaks is associated nucleotide damage, including base loss (abasic or apurinic/apyrimidinic (AP) sites). At single-strand breaks, 5'-terminal abasic sites are excised by the 5'-deoxyribose-5-phosphate (5'-dRP) lyase activity of DNA polymerase beta (pol beta): 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 lyases, 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.

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Title: Ku is a 5'-dRP/AP lyase that excises nucleotide damage near broken ends
Creators: Steven A Roberts - 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
Natasha Strande
Martin D Burkhalter
Christina Strom
Jody M Havener
Paul Hasty
Dale A Ramsden
Publication Details: Nature (London), Vol.464(7292), pp.1214-1217
Academic Unit: Molecular Biosciences, School of
Publisher: England
Grant note: P01 AG17242 / NIA NIH HHS R01 CA076317 / NCI NIH HHS R01 CA084442-10 / NCI NIH HHS R01 CA76317-05A1 / NCI NIH HHS R01 CA084442 / NCI NIH HHS CA 84442 / NCI NIH HHS P01 AG017242 / NIA NIH HHS
Identifiers: 99900546832301842
Language: English
Resource Type: Journal article