title: New insights into the GINS complex explain the controversy between existing structural models.
abstract: GINS is a key component of eukaryotic replicative forks and is composed of four subunits (Sld5, Psf1, Psf2, Psf3). To explain the discrepancy between structural data from crystallography and electron microscopy (EM), we show that GINS is a compact tetramer in solution as observed in crystal structures, but also forms a double-tetrameric population, detectable by EM. This may represent an intermediate step towards the assembly of two replicative helicase complexes at origins, moving in opposite directions within the replication bubble. Reconstruction of the double-tetrameric form, combined with small-angle X-ray scattering data, allows the localisation of the B domain of the Psf1 subunit in the free GINS complex, which was not visible in previous studies and is essential for the formation of a functional replication fork.
authors.affiliation: Department of Life Sciences, Imperial College London, London, United Kingdom.
authors.forename: Marta
authors.initials: M
authors.lastname: Carroni
authors.affiliation: Structural Biology Laboratory, Elettra - Sincrotrone Trieste, Trieste 34149, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: De March
authors.affiliation: Department of Life Sciences, Imperial College London, London, United Kingdom.|Structural Biology Laboratory, Elettra - Sincrotrone Trieste, Trieste 34149, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Medagli
authors.affiliation: Structural Biology Laboratory, Elettra - Sincrotrone Trieste, Trieste 34149, Italy.
authors.forename: Ivet
authors.initials: I
authors.lastname: Krastanova
authors.affiliation: Mill Hill Laboratory, The Francis Crick Institute, The Ridgeway, Mill Hill, London NW7 1AA, UK.
authors.forename: Ian A
authors.initials: IA
authors.lastname: Taylor
authors.affiliation: Institute of Inorganic Chemistry, Graz University of Technology, Stremayerg. 6/IV, 8010 Graz, Austria.
authors.forename: Heinz
authors.initials: H
authors.lastname: Amenitsch
authors.affiliation: Division of Microbial Genetics, National Institute of Genetics, Shizuoka, Japan.
authors.forename: Hiroyuchi
authors.initials: H
authors.lastname: Araki
authors.affiliation: Istituto di Biochimica delle Proteine, Consiglio Nazionale delle Ricerche, Napoli, Italy.
authors.forename: Francesca M
authors.initials: FM
authors.lastname: Pisani
authors.affiliation: Department of Life Sciences, Imperial College London, London, United Kingdom.|Protein Data Bank in Europe, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK.
authors.forename: Ardan
authors.initials: A
authors.lastname: Patwardhan
authors.affiliation: Department of Life Sciences, Imperial College London, London, United Kingdom.|Structural Biology Laboratory, Elettra - Sincrotrone Trieste, Trieste 34149, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Onesti
mesh_terms: D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry* / Q000378:metabolism; D018360:Crystallography, X-Ray; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008854:Microscopy, Electron; D008958:Models, Molecular; D055503:Protein Multimerization; D053838:Scattering, Small Angle
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; C547590:GINS1 protein, human; C556406:GINS2 protein, human; C521092:GINS3 protein, human; C521091:GINS4 protein, human