Visualizing a new binding site of ncd-motor domain on tubulin.
Ncd is a microtubule minus-end directed motor of the kinesin superfamily. Previously it has been shown that ncd and kinesin motor domains share the same major binding site on microtubules. Here we report a three-dimensional EM reconstruction of negatively stained two-dimensional Zn-induced tubulin crystal sheets (Zn-sheets) decorated with the ncd motor domain at a resolution of 16 A. This work has revealed a second specific binding site for the ncd motor domain. The motor binding site on the tubulin Zn-sheets spans both alpha and beta tubulin subunits. This binding site is located at a position different from the previously identified ncd binding site on microtubules and may play a role in motor function.
Han
Y
Y
Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
Sablin
E P
EP
Nogales
E
E
Fletterick
R J
RJ
Downing
K H
KH
D000818:Animals; D001665:Binding Sites; D003461:Crystallography / Q000379:methods; D004330:Drosophila; D029721:Drosophila Proteins; D004583:Electrons; D016547:Kinesins / Q000737:chemistry*; D008854:Microscopy, Electron; D008870:Microtubules / Q000737:chemistry; D008958:Models, Molecular; D011487:Protein Conformation; D014404:Tubulin / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry
D029721:Drosophila Proteins; D014404:Tubulin; C066696:ncd protein, Drosophila; D016547:Kinesins; D015032:Zinc