1. CONFORMATIONAL CHANGES AT THE NUCLEOTIDE-BINDING SITE OF KINESIN-FAMILY MOTORS ED PATE WSU

2. FORCE GENERATION IN MUSCLE IS PRODUCED BY THE INTERACTION OF TWO PROTEINS: ACTIN AND MYOSIN MYOSIN ACTIN

3. MYOSIN KINESIN

5. NUCLEOTIDE BINDING SITE MYOSINKINESIN

6. NCDMYOSIN COMPARISON OF NCD AND MYOSIN BINDING SITES

8. LOCATION OFKINESIN CYS-188

9. VAN’T HOFF ANALYSIS SHOWS  H 0 = -100 KJ/MOL FOR THE TRANSITION

11. ANALOG  ANGLE EPR ncd SSL-NANDP44° SL-NANDP>28° 2'-SLADP12° 3'-SLADP>12° 2', 3'-SLADP>16° kinesin SSL-NANDP35° SL-NANDP32° 2'-SLADP>10° 3'-SLADP11° 2', 3'-SLADP>18° SUMMARY OF CONE ANGLE CHANGES ON BINDING TO MICROTUBULES

12. CONSTRUCTION OF NCD WITH SWITCH 1 CLOSED ADP P-LOOP SWITCH 2 NCD SWITCH 1

13. CONSTRUCTION OF NCD WITH SWITCH 1 CLOSED P-LOOP SWITCH 2 NCD SWITCH 1 MYOSIN SWITCH 1

14. CONSTRUCTION OF NCD WITH SWITCH 1 CLOSED ADP P-LOOP SWITCH 2 NCD SWITCH 1 MODIFIED NCD SWITCH 1 12 Å

15. POTENTIAL ENERGY COMPONENTS FROM BONDED INTERACTIONS Stretch Flex Torsion

16. POTENTIAL ENERGY COMPONENTS FROM NON-BONDED INTERACTIONS Coulomb Interaction

18. SWITCH 1 P-LOOP ADPSWITCH 1 SWITCH 2 P-LOOP THE OPEN SWITCH 1 CONFORMATION IS STABLE

19. P-LOOP SWITCH 1 P-LOOP SWITCH 2 THE CLOSED SWITCH 1 CONFORMATION IS STABLE

20. MOLECULAR DYNAMICS RESULTS Open structure (x-ray) stable at 300 K (ADP, ATP, APO) Closed structure (model) stable at 300 K (ADP, ATP, APO) Closed Open Open and closed structures Are local minima on a global free energy surface. Test with high temperature Dynamics. GG Energy barrier

21. INFLUENCE OF SWITCH 1 ON EPR PROBES

22. ANGLE -90900 ANGULAR DISTRIBUTION FOR SSL-NANDP IN THE OPEN AND CLOSED CONFORMATIONS

25. COORDINATION AT THE OPEN NUCLEOTIDE SITE

26. COORDINATION AT THE CLOSED NUCEOTIDE SITE

27. MYOSIN KINESIN

29. CONCLUSIONS 1. Comparison with myosin suggests a new structural state of kinesin-family motors involving a closing of the nucleotide site. 2. Spectroscopic data show the nucleotide site closes when kinesin binds to microtubules. 3. MD shows the open and closed binding-site conformations of kinesin-family motors explain the changes in mobility of nucleotide analog EPR probes upon binding to microtubules. 4. MD shows the closed state is essential for nucleotide hydrolysis and force production.

30. COLLABORATORS ROGER COOKE, UCSFRALPH YOUNT, WSU Nariman NaberXiaoru Chen Marija MatuskaJean Grammer Kathy Franks-Skiba PETER KOLLMAN, UCSF RON VALE, UCSF Todd Minehardt Sarah Rice ROBERTO CAR, PRINCETON DAVID ADCOCK, LONE STAR BIOTECH