αA-F	α-helices A to F from HD
ADP	ADP-ribose
ADP	Adenosine diphosphate
ADPr	ADP-ribosylation
AFM	Atomic force microscopy
ALC1	Amplified in liver cancer 1
AP site	Apurinic/apyrimidinic site
ARH	ADP-ribose hydrolase
ART	ADP-ribosyl transferase
ATM	Ataxia telangiectasia mutated
BER	Base excision repair
BRCA1/2	Breast cancer
BRCT	BRCA1 C-terminal domain
CAT	Catalytic domain
CHD2	Chromodomain-helicase-DNA-binding protein 2
CHD4	Chromodomain-helicase-DNA-binding protein 4
Cryo-EM	Cryo-electron microscopy
DDB1/2	DNA damage binding proteins 1 and 2
DDR	DNA damage response
D-loop	Donor loop of the active site
DNA	Deoxyribonucleic acid
DNAPKcs	DNA protein kinase catalytic subunit
DSB	Double-strand break
ETD	Electron transfer dissociation
FACT	Facilitate chromatin transcription
gap	Missing nucleotide, form of DNA break
GG-NER	Global genome nucleotide excision repair
H1	Linker histone
H2A, H2B, H3, H4	Core histones
HD	Helical domain
HDX-MS	Hydrogen/deuterium exchange-mass spectrometry
HeLa	Cervical cancer cell line from Henrietta Lacks
HPF1	Histone PARylation factor 1
HR	Homologous recombination
HYE	Conserved histidone, tyrosine, glutamic acid motif
IC50	Half maximal inhibitory concentration
Kd	Dissociation constant
MAR	Mono (ADP-ribose)
MARylation	Mono-ADP-ribosylation
MRE11	Meotic recombination 11
MS	Mass spectrometry
NAD+	Nicotinamide adenine dinucleotide
NHEJ	Non-homologous end joining
NMNAT-1	Nicotinamide/nicotinic acid mononucleotide adenylyltransferase 1
NMR	Nuclear magnetic resonance
NOESY	Nuclear overhauser effect spectroscopy
NuRD	Nucleosome remodeling and deacetylase
p53	Tumour suppressor named after its apparent MW on SDS-PAGE gel, 53 kDa
PAR	Poly (ADP-ribose)
PARG	Poly(ADP-ribose) glycohydrolase
PARP1	Poly (ADP-ribose) polymerase 1
PARP2	Poly (ADP-ribose) polymerase 2
PARP3	Poly (ADP-ribose) polymerase 3
PARPi	PARP inhibitor
PARylation	Poly-ADP-ribosylation
PDB	Protein data bank
PTM	Post-translational modification
RMSD	Root mean square deviation
RNA	Ribonucleic acid
SAP	SAF/acinus/PIAS
SNF2	Sucrose non-fermenting protein 2
SSB	Single-strand break
TDP1	Tyrosyl-DNA phosphodiesterase 1
Top1cc	TOP1 cleavage complexes
V(D)J	Variable, diversity and joining
WGR	Conserved tryptophan, glycine, arginine-motif domain
XRCC1	X-ray repair cross complementing group 1
Zn1	Zinc finger 1
Zn2	Zinc finger 2
Zn3	Zinc finger 3