Crystal structure of Zen4 in the apo state reveals a missing conformation of kinesin
Guan, R., Zhang, L., Su, Q.P., Mickolajczyk, K.J., Chen, G.Y., Hancock, W.O., Sun, Y., Zhao, Y., Chen, Z.(2017) Nat Commun 8: 14951-14951
- PubMed: 28393873 
- DOI: https://doi.org/10.1038/ncomms14951
- Primary Citation of Related Structures:  
5X3E - PubMed Abstract: 
Kinesins hydrolyse ATP to transport intracellular cargoes along microtubules. Kinesin neck linker (NL) functions as the central mechano-chemical coupling element by changing its conformation through the ATPase cycle. Here we report the crystal structure of kinesin-6 Zen4 in a nucleotide-free, apo state, with the NL initial segment (NIS) adopting a backward-docked conformation and the preceding α6 helix partially melted. Single-molecule fluorescence resonance energy transfer (smFRET) analyses indicate the NIS of kinesin-1 undergoes similar conformational changes under tension in the two-head bound (2HB) state, whereas it is largely disordered without tension. The backward-docked structure of NIS is essential for motility of the motor. Our findings reveal a key missing conformation of kinesins, which provides the structural basis of the stable 2HB state and offers a tension-based rationale for an optimal NL length to ensure processivity of the motor.
Organizational Affiliation: 
MOE Key Laboratory of Protein Science, Tsinghua University, Beijing 100084, China.