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KIF1D is a fast non‐processive kinesin that demonstrates novel K‐loop‐dependent mechanochemistry
Author(s) -
Rogers Kevin R.,
Weiss Stefan,
Crevel Isabelle,
Brophy Peter J.,
Geeves Michael,
Cross Robert
Publication year - 2001
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/20.18.5101
Subject(s) - mechanochemistry , biology , kinesin , loop (graph theory) , biophysics , microbiology and biotechnology , genetics , microtubule , nanotechnology , materials science , mathematics , combinatorics
The KIF1 subfamily members are monomeric and contain a number of amino acid inserts in surface loops. A particularly striking insertion of several lysine/arginine residues occurs in L12 and is called the K‐loop. Two recent studies have employed both kinetic and single‐molecule methods to investigate KIF1 motor properties and have produced very different conclusions about how these motors generate motility. Here we show that a hitherto unstudied member of this group, KIF1D, is not chemically processive and drives fast motility despite demonstrating a slow ATPase. The K‐loop of KIF1D was analysed by deletion and insertion mutagenesis coupled with characterization by steady state and transient kinetics. Together, the results indicate that the K‐loop not only increases the affinity of the motor for the MT, but crucially also inhibits its subsequent isomerization from weak to strong binding, with coupled ADP release. By stabilizing the weak binding, the K‐loop establishes a pool of motors primed to undergo their power stroke.