Altmeyer M Messner S Hassa PO Fey M Hottiger MO 2009 Poly(ADP-ribose) polymerase 1 (PARP1) synthesizes poly(ADP-ribose) (PAR) using nicotinamide adenine dinucleotide (NAD) as a substrate. Despite intensive research on the cellular functions of PARP1, the molecular mechanism of PAR formation has not been comprehensively understood. In this study, we elucidate the molecular mechanisms of poly(ADP-ribosyl)ation and identify PAR acceptor sites. Generation of different chimera proteins revealed that the amino-terminal domains of PARP1, PARP2 and PARP3 cooperate tightly with their corresponding catalytic domains. The DNA-dependent interaction between the amino-terminal DNA-binding domain and the catalytic domain of PARP1 increased V(max) and decreased the K(m) for NAD. Furthermore, we show that glutamic acid residues in the auto-modification domain of PARP1 are not required for PAR formation. Instead, we identify individual lysine residues as acceptor sites for ADP-ribosylation. Together, our findings provide novel mechanistic insights into PAR synthesis with significant relevance for the different biological functions of PARP family members. application/pdf https://sonar.ch/global/documents/4356 eng info:eu-repo/semantics/altIdentifier/doi/10.1093/nar/gkp229 info:eu-repo/semantics/altIdentifier/pmid/19372272 info:eu-repo/semantics/openAccess Nucleic acids research. - 2009 Catalytic Domain Cell Cycle Proteins DNA Glutamic Acid Humans Lysine Poly (ADP-Ribose) Polymerase-1 Poly Adenosine Diphosphate Ribose Poly(ADP-ribose) Polymerases Protein Multimerization Protein Structure, Tertiary Molecular mechanism of poly(ADP-ribosyl)ation by PARP1 and identification of lysine residues as ADP-ribose acceptor sites. http://purl.org/coar/resource_type/c_6501