title: The fidelity of the ligation step determines how ends are resolved during nonhomologous end joining.
abstract: Nonhomologous end joining (NHEJ) can effectively resolve chromosome breaks despite diverse end structures; however, it is unclear how the steps employed for resolution are determined. We sought to address this question by analysing cellular NHEJ of ends with systematically mispaired and damaged termini. We show NHEJ is uniquely proficient at bypassing subtle terminal mispairs and radiomimetic damage by direct ligation. Nevertheless, bypass ability varies widely, with increases in mispair severity gradually reducing bypass products from 85 to 6%. End-processing by nucleases and polymerases is increased to compensate, although paths with the fewest number of steps to generate a substrate suitable for ligation are favoured. Thus, both the frequency and nature of end processing are tailored to meet the needs of the ligation step. We propose a model where the ligase organizes all steps during NHEJ within the stable paired-end complex to limit end processing and associated errors.
authors.affiliation: Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
authors.forename: Crystal A
authors.initials: CA
authors.lastname: Waters
authors.affiliation: Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
authors.forename: Natasha T
authors.initials: NT
authors.lastname: Strande
authors.affiliation: Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
authors.forename: John M
authors.initials: JM
authors.lastname: Pryor
authors.affiliation: Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
authors.forename: Christina N
authors.initials: CN
authors.lastname: Strom
authors.affiliation: Department of Genetics, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
authors.forename: Piotr
authors.initials: P
authors.lastname: Mieczkowski
authors.affiliation: Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
authors.forename: Martin D
authors.initials: MD
authors.lastname: Burkhalter
authors.affiliation: Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnosota, 6-155 Jackson Hall, 321 Church Street SE, Minneapolis, Minnesota 55455, USA.
authors.forename: Sehyun
authors.initials: S
authors.lastname: Oh
authors.affiliation: Biostatistics core, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
authors.forename: Bahjat F
authors.initials: BF
authors.lastname: Qaqish
authors.affiliation: Biostatistics core, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
authors.forename: Dominic T
authors.initials: DT
authors.lastname: Moore
authors.affiliation: Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnosota, 6-155 Jackson Hall, 321 Church Street SE, Minneapolis, Minnesota 55455, USA.
authors.forename: Eric A
authors.initials: EA
authors.lastname: Hendrickson
authors.affiliation: Department of Biochemistry and Biophysics and Curriculum in Genetics and Molecular Biology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
authors.forename: Dale A
authors.initials: DA
authors.lastname: Ramsden
mesh_terms: D059766:DNA End-Joining Repair; D045325:HCT116 Cells; D006801:Humans