title: Near-atomic cryo-EM structure of PRC1 bound to the microtubule.
abstract: Proteins that associate with microtubules (MTs) are crucial to generate MT arrays and establish different cellular architectures. One example is PRC1 (protein regulator of cytokinesis 1), which cross-links antiparallel MTs and is essential for the completion of mitosis and cytokinesis. Here we describe a 4-Å-resolution cryo-EM structure of monomeric PRC1 bound to MTs. Residues in the spectrin domain of PRC1 contacting the MT are highly conserved and interact with the same pocket recognized by kinesin. We additionally found that PRC1 promotes MT assembly even in the presence of the MT stabilizer taxol. Interestingly, the angle of the spectrin domain on the MT surface corresponds to the previously observed cross-bridge angle between MTs cross-linked by full-length, dimeric PRC1. This finding, together with molecular dynamic simulations describing the intrinsic flexibility of PRC1, suggests that the MT-spectrin domain interface determines the geometry of the MT arrays cross-linked by PRC1.
authors: Molecular Biophysics and Integrative Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720; Howard Hughes Medical Institute, University of California, Berkeley, CA 94720;
authors: Elizabeth H
authors: EH
authors: Kellogg
authors: Biophysics Graduate Group, University of California, Berkeley, CA 94720;
authors: Stuart
authors: S
authors: Howes
authors: Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065;
authors: Shih-Chieh
authors: SC
authors: Ti
authors: Department of Biological Physical Chemistry, Rocasolano Physical Chemistry Institute, Consejo Superior de Investigaciones Científicas, Madrid 28006, Spain;
authors: Erney
authors: E
authors: Ramírez-Aportela
authors: Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065;
authors: Tarun M
authors: TM
authors: Kapoor
authors: Department of Biological Physical Chemistry, Rocasolano Physical Chemistry Institute, Consejo Superior de Investigaciones Científicas, Madrid 28006, Spain;
authors: Pablo
authors: P
authors: Chacón
authors: Molecular Biophysics and Integrative Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720; Howard Hughes Medical Institute, University of California, Berkeley, CA 94720; California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720; Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720 enogales@lbl.gov.
authors: Eva
authors: E
authors: Nogales
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D001665:Binding Sites; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure*; D020285:Cryoelectron Microscopy; D018360:Crystallography, X-Ray; D015870:Gene Expression; D006801:Humans; D016547:Kinesins / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure*; D008870:Microtubules / Q000378:metabolism / Q000648:ultrastructure*; D056004:Molecular Dynamics Simulation; D017239:Paclitaxel / Q000737:chemistry; D011485:Protein Binding; D000072756:Protein Conformation, alpha-Helical; D000072757:Protein Conformation, beta-Strand; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization; D021122:Protein Subunits / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D013552:Swine; D014404:Tubulin / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure*; D050257:Tubulin Modulators / Q000737:chemistry
chemical_list: D018797:Cell Cycle Proteins; C116662:PRC1 protein, human; D021122:Protein Subunits; D011994:Recombinant Proteins; D014404:Tubulin; D050257:Tubulin Modulators; D016547:Kinesins; D017239:Paclitaxel
keywords: MAPs; PRC1; cryo-EM; cytoskeleton; microtubules