Cloning and expression of kinesins from the thermophilic fungus Thermomyces lanuginosus

The motor domain regions of three novel members of the kinesin superfamily TLKIF1, TLKIFC, and TLBIMC were identified in a thermophilic fungus Thermom yces lanuginosus. Based on sequence similarity, they were classified as mem bers 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 activ e. TLKIF1 is a monomeric kinesin motor, which in a gliding motility assay d isplays a robust plus-directed microtubule movement up to 2 mu m/s. The dis covery of TLKTF1 also demonstrates that a family of kinesin motors not prev iously found in fungi may in fact be used in this group of organisms.