Design principles of a microtubule polymerase
Stu2/XMAP215 microtubule polymerases use multiple tubulin-binding TOG domains and a lattice-binding basic region to processively promote faster elongation. How the domain composition and organization of these proteins dictate polymerase activity, end localization, and processivity is unknown. We sho...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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eLife Sciences Publications Ltd
2018-06-01
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| Series: | eLife |
| Subjects: | |
| Online Access: | https://elifesciences.org/articles/34574 |
| _version_ | 1811253382110773248 |
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| author | Elisabeth A Geyer Matthew P Miller Chad A Brautigam Sue Biggins Luke M Rice |
| author_facet | Elisabeth A Geyer Matthew P Miller Chad A Brautigam Sue Biggins Luke M Rice |
| author_sort | Elisabeth A Geyer |
| collection | DOAJ |
| description | Stu2/XMAP215 microtubule polymerases use multiple tubulin-binding TOG domains and a lattice-binding basic region to processively promote faster elongation. How the domain composition and organization of these proteins dictate polymerase activity, end localization, and processivity is unknown. We show that polymerase activity does not require different kinds of TOGs, nor are there strict requirements for how the TOGs are linked. We identify an unexpected antagonism between the tubulin-binding TOGs and the lattice-binding basic region: lattice binding by the basic region is weak when at least two TOGs engage tubulins, strong when TOGs are empty. End-localization of Stu2 requires unpolymerized tubulin, at least two TOGs, and polymerase competence. We propose a ‘ratcheting’ model for processivity: transfer of tubulin from TOGs to the lattice activates the basic region, retaining the polymerase at the end for subsequent rounds of tubulin binding and incorporation. These results clarify design principles of the polymerase. |
| first_indexed | 2024-04-12T16:50:04Z |
| format | Article |
| id | doaj.art-8e0e666aeea8494aa1a4e50021c19aa5 |
| institution | Directory Open Access Journal |
| issn | 2050-084X |
| language | English |
| last_indexed | 2024-04-12T16:50:04Z |
| publishDate | 2018-06-01 |
| publisher | eLife Sciences Publications Ltd |
| record_format | Article |
| series | eLife |
| spelling | doaj.art-8e0e666aeea8494aa1a4e50021c19aa52022-12-22T03:24:26ZengeLife Sciences Publications LtdeLife2050-084X2018-06-01710.7554/eLife.34574Design principles of a microtubule polymeraseElisabeth A Geyer0Matthew P Miller1https://orcid.org/0000-0003-2012-7546Chad A Brautigam2Sue Biggins3https://orcid.org/0000-0002-4499-6319Luke M Rice4https://orcid.org/0000-0001-6551-3307Departments of Biophysics and Biochemistry, UT Southwestern Medical Center, Dallas, United StatesHoward Hughes Medical Institute, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United StatesDepartments of Biophysics and Microbiology, UT Southwestern Medical Center, Dallas, United StatesHoward Hughes Medical Institute, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United StatesDepartments of Biophysics and Biochemistry, UT Southwestern Medical Center, Dallas, United StatesStu2/XMAP215 microtubule polymerases use multiple tubulin-binding TOG domains and a lattice-binding basic region to processively promote faster elongation. How the domain composition and organization of these proteins dictate polymerase activity, end localization, and processivity is unknown. We show that polymerase activity does not require different kinds of TOGs, nor are there strict requirements for how the TOGs are linked. We identify an unexpected antagonism between the tubulin-binding TOGs and the lattice-binding basic region: lattice binding by the basic region is weak when at least two TOGs engage tubulins, strong when TOGs are empty. End-localization of Stu2 requires unpolymerized tubulin, at least two TOGs, and polymerase competence. We propose a ‘ratcheting’ model for processivity: transfer of tubulin from TOGs to the lattice activates the basic region, retaining the polymerase at the end for subsequent rounds of tubulin binding and incorporation. These results clarify design principles of the polymerase.https://elifesciences.org/articles/34574Microtubule dynamicsMicrotubule polymeraseIn vitro reconstitution |
| spellingShingle | Elisabeth A Geyer Matthew P Miller Chad A Brautigam Sue Biggins Luke M Rice Design principles of a microtubule polymerase eLife Microtubule dynamics Microtubule polymerase In vitro reconstitution |
| title | Design principles of a microtubule polymerase |
| title_full | Design principles of a microtubule polymerase |
| title_fullStr | Design principles of a microtubule polymerase |
| title_full_unstemmed | Design principles of a microtubule polymerase |
| title_short | Design principles of a microtubule polymerase |
| title_sort | design principles of a microtubule polymerase |
| topic | Microtubule dynamics Microtubule polymerase In vitro reconstitution |
| url | https://elifesciences.org/articles/34574 |
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