title: The Dimeric Architecture of Checkpoint Kinases Mec1ATR and Tel1ATM Reveal a Common Structural Organization.
abstract: The phosphatidylinositol 3-kinase-related protein kinases are key regulators controlling a wide range of cellular events. The yeast Tel1 and Mec1·Ddc2 complex (ATM and ATR-ATRIP in humans) play pivotal roles in DNA replication, DNA damage signaling, and repair. Here, we present the first structural insight for dimers of Mec1·Ddc2 and Tel1 using single-particle electron microscopy. Both kinases reveal a head to head dimer with one major dimeric interface through the N-terminal HEAT (named after Huntingtin, elongation factor 3, protein phosphatase 2A, and yeast kinase TOR1) repeat. Their dimeric interface is significantly distinct from the interface of mTOR complex 1 dimer, which oligomerizes through two spatially separate interfaces. We also observe different structural organizations of kinase domains of Mec1 and Tel1. The kinase domains in the Mec1·Ddc2 dimer are located in close proximity to each other. However, in the Tel1 dimer they are fully separated, providing potential access of substrates to this kinase, even in its dimeric form.
authors.affiliation: From the Section of Structural Biology, Department of Medicine, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom and.
authors.forename: Marta
authors.initials: M
authors.lastname: Sawicka
authors.affiliation: the Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110.
authors.forename: Paulina H
authors.initials: PH
authors.lastname: Wanrooij
authors.affiliation: From the Section of Structural Biology, Department of Medicine, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom and.
authors.forename: Vidya C
authors.initials: VC
authors.lastname: Darbari
authors.affiliation: the Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110.
authors.forename: Elias
authors.initials: E
authors.lastname: Tannous
authors.affiliation: the Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110.
authors.forename: Sarem
authors.initials: S
authors.lastname: Hailemariam
authors.affiliation: From the Section of Structural Biology, Department of Medicine, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom and.
authors.forename: Daniel
authors.initials: D
authors.lastname: Bose
authors.affiliation: the Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110.
authors.forename: Alena V
authors.initials: AV
authors.lastname: Makarova
authors.affiliation: the Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110 burgers@biochem.wustl.edu.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Burgers
authors.affiliation: From the Section of Structural Biology, Department of Medicine, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom and xiaodong.zhang@imperial.ac.uk.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhang
mesh_terms: D064007:Ataxia Telangiectasia Mutated Proteins / Q000737:chemistry* / Q000235:genetics; D006801:Humans; D000072417:Protein Domains; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D040681:Structural Homology, Protein
chemical_list: C576324:ATM protein, human; C576597:ATR protein, human; D064007:Ataxia Telangiectasia Mutated Proteins
keywords: DNA damage response; checkpoint control; nucleic acid enzymology; phosphatidylinositol kinase (PI Kinase); protein structure; serine/threonine protein kinase