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  • The EMBO Journal (2001) 20, 6226 - 6235
  • doi:10.1093/emboj/20.22.6226

Unusual properties of the fungal conventional kinesin neck domain from Neurospora crassa

Athina Kallipolitou1, Dominga Deluca2, Ulrike Majdic1, Stefan Lakämper3, Robert Cross4, Edgar Meyhöfer3, Luis Moroder2, Manfred Schliwa1 and Günther Woehlke1

  1. Adolf-Butenandt-Institute, Cell Biology 1b, Universität München, Schillerstrasse 42, D-80336 Munich, Germany
  2. Max-Planck-Insitiute for Biochemistry, Department of Bioorganic Chemistry, Am Klopferspitz 18a, D-82152 Martinsried, Germany
  3. Institute for Molecular and Cellular Physiology, Medizinische Hochschule Hannover, Carl-Neuberg-Strasse 1, D-30625 Hannover, Germany
  4. Molecular Motors Group, Marie Curie Research Institute, The Chart, Oxted, Surrey RH8 0TL, UK

Correspondence to:

Günther Woehlke, E-mail: guenther.woehlke@lrz.uni-muenchen.de

Received 17 May 2001; Accepted 21 September 2001; Revised 19 September 2001

Fungal conventional kinesins are unusually fast microtubule motor proteins. To compare the functional organization of fungal and animal conventional kinesins, a set of C-terminal deletion mutants of the Neurospora crassa conventional kinesin, NcKin, was investigated for its biochemical and biophysical properties. While the shortest, monomeric construct comprising the catalytic core and the neck-linker (NcKin343) displays very high steady-state ATPase (kcat = 260/s), constructs including both the full neck and adjacent hinge domains (NcKin400, NcKin433 and NcKin480) show wild-type behaviour: they are dimeric, show fast gliding and slower ATP turnover rates (kcat = 60–84/s), and are chemically processive. Unexpectedly, a construct (NcKin378, corresponding to Drosophila KHC381) that includes just the entire coiled-coil neck is a monomer. Its ATPase activity is slow (kcat = 27/s), and chemical processivity is abolished. Together with a structural analysis of synthetic neck peptides, our data demonstrate that the NcKin neck domain behaves differently from that of animal conventional kinesins and may be tuned to drive fast, processive motility.

  • Keywords:

    • ATPase kinetics,
    • domain analysis,
    • fungal kinesin,
    • processivity,
    • synthetic peptide