REAGENT or RESOURCE	SOURCE	IDENTIFIER
Antibodies
Rabbit polyclonal MRE11	gift from S. P. Jackson, Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge	N/A
Mouse monoclonal RAD50	Millipore	Cat#(13B3/2C6) 05-525; RRID:AB_309782
Rabbit polyclonal NBS1	Novus Biologicals	Cat#NB100-143; RRID:AB_10078050
Mouse monoclonal RNAP II	Abcam	Cat#ab817; RRID:AB_306327
Mouse monoclonal anti-γH2AX	Millipore	Cat#05-636; RRID:AB_309864
CtIP	Bethyl	Cat#A300-488A; RRID: AB_2175262
HA	In house facility	N/A
Chemicals, Peptides, and Recombinant Proteins
Mirin	Sigma-Alrich	Cat#M9948
PFM39	Sigma-Alrich	Cat#SML1839
PFM01	Sigma-Alrich	Cat#SML1735
RNaseOUT	Thermo-Fisher	Cat#10777019
Ribonucleotides	Promega	Cat#P1132
Restriction Enzymes: SmaI	New England Biolabs	Cat#R0141S
α-32P[UTP]	Perkin-Elmer	Cat#NEG507H250UC
5,6-Dichlorobenzimidazole 1-β-D-ribofuranoside	Sigma-Aldrich	Cat#D1916
Glycogen	Thermo-Fisher	Cat#AM9510
RNA loading dye	New England Biolabs	Cat#B0363S
MOPS-EDTA-Sodium Acetate	Sigma-Aldrich	Cat#M5755
RNase H	New England Biolabs	Cat#M0297S
RNase A	Sigma-Aldrich	Cat#R6513
Turbo DNase	Ambion	Cat#AM2238
Gelatin from cold water fish skin	Sigma-Aldrich	Cat#G7765
Lipofectamine® RNAiMAX Transfection Reagent	Thermo-Fisher	Cat#13778030
Phenol:Chloroform:Isoamyl Alcohol 25:24:1 Saturated with 10 mM Tris, pH 8.0, 1 mM EDTA	Sigma-Aldrich	Cat#P2069
Protease Inhibitor	Calbiochem	Cat#539134
Mowiol® 4-88	Sigma-Aldrich	Cat#81381
Dynabeads protein G	Thermo-Fisher	Cat#10004D
α-amanitin	Sigma-Aldrich	Cat#A2263
SsoFast EvaGreen® Supermix	Bio-Rad	Cat#1725201
19:1, acrylamide: bis-acrylamide	Sigma-Aldrich	Cat#A3449
4-OHT	Sigma-Aldrich	Cat#SML1666
UltraPure BSA	Thermo-Fisher	Cat#AM2618
Terminal Transferase	New England Biolabs	Cat#M0315S
Lipofectamine 2000 transfection reagent	Thermo-Fisher	Cat#11668019
Critical Commercial Assays
Superscript IV First Strand cDNA synthesis kit	Thermo-Fisher	Cat#18091200
Maxwell RSC simplyRNA tissue kit	Promega	Cat#218161
Gel Extraction Kit	QIAGEN	Cat#28704
Experimental Models: Cell Lines
HeLa	ATCC	Cat#CCL-2
U2OS NBS1-GFP	Gift from Jiri Bartek, Danish Cancer society’s Institute of Cancer Biology, Copenhagen	N/A
Oligonucleotides
Primers and Oligonucleotides	Sigma-Aldrich	Table S1
siRNA	Sigma-Aldrich	Table S1
Recombinant DNA
I-PpoI	Berkovich et al.,2007	N/A
pICE-HA-MRE11-WT	Chanut et al.,2016	AddgeneCat#82033
pICE-HA-MRE11-H129N	Chanut et al.,2016	AddgeneCat#82034
pICE-HA-MRE11-H63D	Chanut et al.,2016	AddgeneCat#82036
pICE-HA-MRE11- H63S	Chanut et al.,2016	AddgeneCat#82035
pUC19	Invitrogen	N/A
Software and Algorithms
Image Lab	Bio-Rad	N/A
ImageQuant	GE healthcare	N/A
ImageJ	NIH	N/A
Prism	Graph Pad	https://www.graphpad.com/scientificsoftware/prism/