title: Multivalent Microtubule Recognition by Tubulin Tyrosine Ligase-like Family Glutamylases.
abstract: Glutamylation, the most prevalent tubulin posttranslational modification, marks stable microtubules and regulates recruitment and activity of microtubule- interacting proteins. Nine enzymes of the tubulin tyrosine ligase-like (TTLL) family catalyze glutamylation. TTLL7, the most abundant neuronal glutamylase, adds glutamates preferentially to the β-tubulin tail. Coupled with ensemble and single-molecule biochemistry, our hybrid X-ray and cryo-electron microscopy structure of TTLL7 bound to the microtubule delineates a tripartite microtubule recognition strategy. The enzyme uses its core to engage the disordered anionic tails of α- and β-tubulin, and a flexible cationic domain to bind the microtubule and position itself for β-tail modification. Furthermore, we demonstrate that all single-chain TTLLs with known glutamylase activity utilize a cationic microtubule-binding domain analogous to that of TTLL7. Therefore, our work reveals the combined use of folded and intrinsically disordered substrate recognition elements as the molecular basis for specificity among the enzymes primarily responsible for chemically diversifying cellular microtubules.
authors.affiliation: Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Garnham
authors.affiliation: Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA.
authors.forename: Annapurna
authors.initials: A
authors.lastname: Vemu
authors.affiliation: Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Wilson-Kubalek
authors.affiliation: Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA.
authors.forename: Ian
authors.initials: I
authors.lastname: Yu
authors.affiliation: Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Szyk
authors.affiliation: Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Gabriel C
authors.initials: GC
authors.lastname: Lander
authors.affiliation: Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Ronald A
authors.initials: RA
authors.lastname: Milligan
authors.affiliation: Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA; National Heart, Lung and Blood Institute, Bethesda, MD 20892, USA. Electronic address: antonina@mail.nih.gov.
authors.forename: Antonina
authors.initials: A
authors.lastname: Roll-Mecak
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D020285:Cryoelectron Microscopy; D018360:Crystallography, X-Ray; D006801:Humans; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010453:Peptide Synthases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment
chemical_list: D010453:Peptide Synthases; C112698:tubulin polyglutamylase