title: Atomic-resolution structure of the CAP-Gly domain of dynactin on polymeric microtubules determined by magic angle spinning NMR spectroscopy.
abstract: Microtubules and their associated proteins perform a broad array of essential physiological functions, including mitosis, polarization and differentiation, cell migration, and vesicle and organelle transport. As such, they have been extensively studied at multiple levels of resolution (e.g., from structural biology to cell biology). Despite these efforts, there remain significant gaps in our knowledge concerning how microtubule-binding proteins bind to microtubules, how dynamics connect different conformational states, and how these interactions and dynamics affect cellular processes. Structures of microtubule-associated proteins assembled on polymeric microtubules are not known at atomic resolution. Here, we report a structure of the cytoskeleton-associated protein glycine-rich (CAP-Gly) domain of dynactin motor on polymeric microtubules, solved by magic angle spinning NMR spectroscopy. We present the intermolecular interface of CAP-Gly with microtubules, derived by recording direct dipolar contacts between CAP-Gly and tubulin using double rotational echo double resonance (dREDOR)-filtered experiments. Our results indicate that the structure adopted by CAP-Gly varies, particularly around its loop regions, permitting its interaction with multiple binding partners and with the microtubules. To our knowledge, this study reports the first atomic-resolution structure of a microtubule-associated protein on polymeric microtubules. Our approach lays the foundation for atomic-resolution structural analysis of other microtubule-associated motors.
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716;
authors.forename: Si
authors.initials: S
authors.lastname: Yan
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716;
authors.forename: Changmiao
authors.initials: C
authors.lastname: Guo
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716;
authors.forename: Guangjin
authors.initials: G
authors.lastname: Hou
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716;
authors.forename: Huilan
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716;
authors.forename: Xingyu
authors.initials: X
authors.lastname: Lu
authors.affiliation: Department of Molecular Medicine, Beckman Research Institute of City of Hope, Duarte, CA 91010.
authors.forename: John Charles
authors.initials: JC
authors.lastname: Williams
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716; tpolenov@udel.edu.
authors.forename: Tatyana
authors.initials: T
authors.lastname: Polenova
mesh_terms: D000595:Amino Acid Sequence; D002138:Calibration; D000072159:Dynactin Complex; D005998:Glycine / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008869:Microtubule-Associated Proteins / Q000737:chemistry*; D008870:Microtubules / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D058105:Polymerization; D017434:Protein Structure, Tertiary
chemical_list: D000072159:Dynactin Complex; D008869:Microtubule-Associated Proteins; D005998:Glycine
keywords: dynactin's CAP-Gly domain; intermolecular interface determination; magic angle spinning NMR; microtubules; structure determination