X-ray and Cryo-EM structures reveal mutual conformational changes of Kinesin and GTP-state microtubules upon binding.

The University of Tokyo Cell Biology / Anatomy, Tokyo, Tokyo, University of Tokyo Graduate School of Medicine Graduate School of Molecular Structure Dynamics

National Institute of Advanced Industrial Science and Technology Biomedical Research Center, Tsukuba City

The University of Tokyo The University of Tokyo The University of Tokyo Graduate School of Medicine Graduate School of Medicine Graduate School of Medicine Department of Molecular Structure Dynamics Japan National University Genome Medical Research Center (JEGMR) Jeddah Jeddah hirokawa@mu-tokyo.ac.jp

Molecular motor kinesins migrate at an early stage using energy from ATP hydrolysis along microtubules with ADP release. In neurons, kinesin-1 / KIF5C binds to GTP-state microtubules preferentially to GDP-state microtubules and selectively enters axons in a number of processes; however, nucleotide-free KIF5C atoms Since the structure can not be used, its molecular mechanism remains unresolved. Here we propose a crystal structure of nucleotide - free KIF5C complexed with microtubules in GTP state and a low - temperature electron microscope structure of nucleotide - free KIF5C. This structure explains the mutual conformational change induced by the interaction between GTP-state microtubules and KIF 5 C. KIF 5C demonstrates that mobile switches I and II are stabilized by L11 and the first part of the cervical joint and promote from efficient ADP release and weak transition of KIF 5C microtubule affinity to a strong transition "Strict conformation "Is achieved. Conformational changes in tubulin potentiate the longitudinal contact of microtubules in the GTP state in a manner similar to GDP-paclitaxel microtubules. These results and functional analyzes provide a molecular mechanism by which KIF 5 C binds preferentially to microtubules of GTP status.

Single particle low temperature electron microscopy (cryo-EM) is an increasingly popular technique used by structural biologists to solve atomic level structures. This technique complements X-ray crystallography since it reveals the details of the structure without having to crystallize the sample. Examination of the frozen hydration sample in glassy (noncrystalline) ice maintains the ultrafine structure of the sample and the buffer and ligands are dispensed from their natural state. Cryo-EM also complements structural studies using nuclear magnetic resonance (NMR). Because it allows for studies of samples larger than 150 kDa. Structural biologists often use low temperature EM to study intermolecular interactions in viruses, small organelles, and polymeric bioconjugates, as well as supramolecular aggregates or mechanisms.

Molecular motor kinesins migrate at an early stage using energy from ATP hydrolysis along microtubules with ADP release. In neurons, kinesin-1 / KIF5C binds to GTP-state microtubules preferentially to GDP-state microtubules and selectively enters axons in a number of processes; however, nucleotide-free KIF5C atoms Since the structure can not be used, its molecular mechanism remains unresolved. Here we propose a crystal structure of nucleotide - free KIF5C complexed with microtubules in GTP state and a low - temperature electron microscope structure of nucleotide - free KIF5C. This structure explains the mutual conformational change induced by the interaction between GTP-state microtubules and KIF 5 C. KIF 5C is a "strict" mobile switch I and II that is stabilized by the first part of L11 and cervical joints, promoting efficient ADP release and transitioning from a weak transition of KIF 5C microtubule affinity to a strong transition Conformation "is achieved.

X - ray and Cryo - EM structure show mutual conformational change of kinesin and GTP state microtubules after binding

Venki Ramakrishnan, a structural biologist at Molecular Biology Laboratory, shared the 2009 Nobel Prize in chemistry for elucidating the ribosome structure using X-ray crystallography. After learning about Natural Journalist's award, he said, "People who think it should be awesome! Nobel prize." Structural biologist Bernoît Zuber of Bern University in Switzerland got a doctorate in Dubossee , His leader believes that cryo - EM always believes that cryo - EM will be an important tool even if mocking the "blobology" of the low resolution molecular image taken by CryoEm. "He has a vision and everyone said to him that it is just a dream, he is convinced of this," Zubel said.