| Автор | Hou, Ruizheng |
| Автор | Wang, Zhisong |
| Дата выпуска | 2010-09-01 |
| dc.description | Kar3 is a kinesin motor that facilitates chromosome segregation during cell division. Unlike many members of the kinesin superfamily, Kar3 forms a heterodimer with non-motor protein Vik1 or Cik1 in vivo. The heterodimers show ATP-driven minus-end directed motility along a microtubule (MT) lattice, and also serve as depolymerase at the MT ends. The molecular mechanisms behind this dual functionality remain mysterious. Here, a molecular mechanical model for the Kar3/Vik1 heterodimer based on structural, kinetic and motility data reveals a long-range chemomechanical transmission mechanism that resembles a familiar fishing tactic. By this molecular ‘fishing’, ATP-binding to Kar3 dissociates catalytically inactive Vik1 off MT to facilitate minus-end sliding of the dimer on the MT lattice. When the dimer binds the frayed ends of MT, the fishing channels ATP hydrolysis energy into MT deploymerization by a mechanochemical effect. The molecular fishing thus provides a unified mechanistic ground for Kar3's dual functionality. The fishing-promoted depolymerization differs from the depolymerase mechanisms found in homodimeric kinesins. The fishing also enables intermolecular coordination with a chemomechanical coupling feature different from the paradigmatic pattern of homodimeric motors. This study rationalizes some puzzling experimental observation, and suggests new experiments for further elucidation of the fishing mechanism. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Копирайт | 2010 IOP Publishing Ltd |
| Название | A coordinated molecular ‘fishing’ mechanism in heterodimeric kinesin |
| Тип | paper |
| DOI | 10.1088/1478-3975/7/3/036003 |
| Electronic ISSN | 1478-3975 |
| Print ISSN | 1478-3967 |
| Журнал | Physical Biology |
| Том | 7 |
| Первая страница | 36003 |
| Последняя страница | 36014 |
| Аффилиация | Wang, Zhisong; |
| Аффилиация | Hou, Ruizheng; Department of Physics, NUS Graduate School for Integrative Sciences and Engineering, and Center for Computational Science & Engineering, National University of Singapore, Singapore 117542 |
| Выпуск | 3 |
