title: Structure of p15(PAF)-PCNA complex and implications for clamp sliding during DNA replication and repair.
abstract: The intrinsically disordered protein p15(PAF) regulates DNA replication and repair by binding to the proliferating cell nuclear antigen (PCNA) sliding clamp. We present the structure of the human p15(PAF)-PCNA complex. Crystallography and NMR show the central PCNA-interacting protein motif (PIP-box) of p15(PAF) tightly bound to the front-face of PCNA. In contrast to other PCNA-interacting proteins, p15(PAF) also contacts the inside of, and passes through, the PCNA ring. The disordered p15(PAF) termini emerge at opposite faces of the ring, but remain protected from 20S proteasomal degradation. Both free and PCNA-bound p15(PAF) binds DNA mainly through its histone-like N-terminal tail, while PCNA does not, and a model of the ternary complex with DNA inside the PCNA ring is consistent with electron micrographs. We propose that p15(PAF) acts as a flexible drag that regulates PCNA sliding along the DNA and facilitates the switch from replicative to translesion synthesis polymerase binding.
authors.affiliation: Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia Edificio 800, 48160 Derio, Spain.
authors.forename: Alfredo
authors.initials: A
authors.lastname: De Biasio
authors.affiliation: Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia Edificio 800, 48160 Derio, Spain.
authors.forename: Alain Ibáñez
authors.initials: AI
authors.lastname: de Opakua
authors.affiliation: 1] Structural Biology and Biocomputing Programme, Centro Nacional de Investigaciones Oncológicas, Melchor Fernández Almagro 3, 28029 Madrid, Spain [2] Protein Structure and Function Program, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
authors.forename: Gulnahar B
authors.initials: GB
authors.lastname: Mortuza
authors.affiliation: Structural Biology and Biocomputing Programme, Centro Nacional de Investigaciones Oncológicas, Melchor Fernández Almagro 3, 28029 Madrid, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Molina
authors.affiliation: Centre de Biochimie Structurale, INSERM U1054, CNRS UMR 5048, Université Montpellier 1 and 2, 29 rue de Navacelles, 34090 Montpellier, France.
authors.forename: Tiago N
authors.initials: TN
authors.lastname: Cordeiro
authors.affiliation: Department of Physical Chemistry and Institute of Biotechnology, Universidad de Granada, Fuentenueva s/n, 18071 Granada, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Castillo
authors.affiliation: Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia Edificio 800, 48160 Derio, Spain.
authors.forename: Maider
authors.initials: M
authors.lastname: Villate
authors.affiliation: Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia Edificio 800, 48160 Derio, Spain.
authors.forename: Nekane
authors.initials: N
authors.lastname: Merino
authors.affiliation: Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia Edificio 800, 48160 Derio, Spain.
authors.forename: Sandra
authors.initials: S
authors.lastname: Delgado
authors.affiliation: Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia Edificio 800, 48160 Derio, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Gil-Cartón
authors.affiliation: Department of Physical Chemistry and Institute of Biotechnology, Universidad de Granada, Fuentenueva s/n, 18071 Granada, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Luque
authors.affiliation: Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia Edificio 800, 48160 Derio, Spain.
authors.forename: Tammo
authors.initials: T
authors.lastname: Diercks
authors.affiliation: Centre de Biochimie Structurale, INSERM U1054, CNRS UMR 5048, Université Montpellier 1 and 2, 29 rue de Navacelles, 34090 Montpellier, France.
authors.forename: Pau
authors.initials: P
authors.lastname: Bernadó
authors.affiliation: 1] Structural Biology and Biocomputing Programme, Centro Nacional de Investigaciones Oncológicas, Melchor Fernández Almagro 3, 28029 Madrid, Spain [2] Department of Physical Chemistry and Institute of Biotechnology, Universidad de Granada, Fuentenueva s/n, 18071 Granada, Spain.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Montoya
authors.affiliation: 1] Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia Edificio 800, 48160 Derio, Spain [2] IKERBASQUE, Basque Foundation for Science, María Díaz de Haro 3, 48013 Bilbao, Spain.
authors.forename: Francisco J
authors.identifier: 0000000325454319
authors.initials: FJ
authors.lastname: Blanco
mesh_terms: D020816:Amino Acid Motifs; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D004260:DNA Repair; D004261:DNA Replication; D004268:DNA-Binding Proteins; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D064267:Intrinsically Disordered Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D018809:Proliferating Cell Nuclear Antigen / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D059748:Proteolysis; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013816:Thermodynamics
chemical_list: D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D064267:Intrinsically Disordered Proteins; C425208:PCLAF protein, human; D018809:Proliferating Cell Nuclear Antigen; D011994:Recombinant Proteins; D004247:DNA; D046988:Proteasome Endopeptidase Complex