REVERSING A BACKWARDS MOTOR

Nod, a kinesin-related microtubule motor protein that moves the 'wrong ' way on microtubules, towards the minus ends, has now been made to mo ve like kinesin, towards plus ends, by fusing regions from outside the kinesin motor domain to the Nod motor.(1,2) Since it is the kinesin m otor domain that binds to and moves on the microtubule, the finding th at regions outside the motor domain can confer directionality of Ncd m ovement is remarkable-it implies a structural basis for motor polarity . Here we consider this finding from a structural point of view and di scuss the implications for motor function and evolution. BioEssays 20. 108-112, 1998. (C) 1998 John Wiley a Sons, Inc.