Direct measurement of conformational strain energy in protofilaments curling outward from disassembling microtubule tips.

ABSTRACT: Disassembling microtubules can generate movement independently of motor enzymes, especially at kinetochores where they drive chromosome motility. A popular explanation is the 'conformational wave' model, in which protofilaments pull on the kinetochore as they curl outward from a disassembling tip. But whether protofilaments can work efficiently via this spring-like mechanism has been unclear. By modifying a previous assay to use recombinant tubulin and feedback-controlled laser trapping, we directly demonstrate the spring-like elasticity of curling protofilaments. Measuring their mechanical work output suggests they carry ~25% of the energy of GTP hydrolysis as bending strain, enabling them to drive movement with efficiency similar to conventional motors. Surprisingly, a β-tubulin mutant t

SUBMITTER: Driver JW 

PROVIDER: S-EPMC5515574 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature