The motor domain regions of three novel members
of the kinesin superfamily TLKIF1, TLKIFC, and TLBIMC were
identified in a thermophilic fungus Thermomyces lanuginosus.
Based on sequence similarity, they were classified as members
of the known kinesin families Unc104/KIF1, KAR3, and BIMC.
TLKIF1 was subsequently expressed in Escherichia coli.
The expression level was high, and the protein was mostly
soluble, easy to purify, and enzymatically active. TLKIF1
is a monomeric kinesin motor, which in a gliding motility
assay displays a robust plus-directed microtubule movement
up to 2 μm/s. The discovery of TLKIF1 also demonstrates
that a family of kinesin motors not previously found in
fungi may in fact be used in this group of organisms.