4ETP

C-terminal motor and motor homology domain of Kar3Vik1 fused to a synthetic heterodimeric coiled coil

Summary for 4ETP

• Entry DOI: 10.2210/pdb4etp/pdb
• Related: 1f9t 1f9u 1f9v 1f9w 1n6m 1U0I 2o0a 3KAR
• Descriptor: Kinesin-like protein KAR3, Spindle pole body-associated protein VIK1, ADENOSINE-5'-DIPHOSPHATE, ... (7 entities in total)
• Functional Keywords: kinesin motor protein, kinesin motor homology domain, karyogamy, mitosis, microtubules, internal vik1 crosslink with n, n-ethylenebis(iodoacetamide), nucleus, motor protein
• Biological source: Saccharomyces cerevisiae (Baker's yeast); More
• Cellular location: Cytoplasm, cytoskeleton, microtubule organizing center, spindle pole body: P17119 Q12045
• Total number of polymer chains: 2
• Total formula weight: 85057.72

Authors

Rank, K.C.,Chen, C.J.,Cope, J.,Porche, K.,Hoenger, A.,Gilbert, S.P.,Rayment, I. (deposition date: 2012-04-24, release date: 2012-06-27, Last modification date: 2024-11-20)

Primary citation

Rank, K.C.,Chen, C.J.,Cope, J.,Porche, K.,Hoenger, A.,Gilbert, S.P.,Rayment, I.
Kar3Vik1, a member of the kinesin-14 superfamily, shows a novel kinesin microtubule binding pattern.
J.Cell Biol., 197:957-970, 2012

PubMed Abstract: Kinesin-14 motors generate microtubule minus-end-directed force used in mitosis and meiosis. These motors are dimeric and operate with a nonprocessive powerstroke mechanism, but the role of the second head in motility has been unclear. In Saccharomyces cerevisiae, the Kinesin-14 Kar3 forms a heterodimer with either Vik1 or Cik1. Vik1 contains a motor homology domain that retains microtubule binding properties but lacks a nucleotide binding site. In this case, both heads are implicated in motility. Here, we show through structural determination of a C-terminal heterodimeric Kar3Vik1, electron microscopy, equilibrium binding, and motility that at the start of the cycle, Kar3Vik1 binds to or occludes two αβ-tubulin subunits on adjacent protofilaments. The cycle begins as Vik1 collides with the microtubule followed by Kar3 microtubule association and ADP release, thereby destabilizing the Vik1-microtubule interaction and positioning the motor for the start of the powerstroke. The results indicate that head-head communication is mediated through the adjoining coiled coil.

PubMed: 22734002
DOI: 10.1083/jcb.201201132

Experimental method

X-RAY DIFFRACTION (2.3 Å)