Conformational changes of p97 during nucleotide hydrolysis determined by small-angle X-Ray scattering.
Valosin-containing protein (VCP)/p97 is an AAA family ATPase that has been implicated in the removal of misfolded proteins from the endoplasmic reticulum and in membrane fusion. p97 forms a homohexamer whose protomers consist of an N-terminal (N) domain responsible for binding to effector proteins, followed by two AAA ATPase domains, D1 and D2. Small-angle X-ray scattering (SAXS) measurements of p97 in the presence of AMP-PNP (ATP state), ADP-AlF(x) (hydrolysis transition state), ADP, or no nucleotide reveal major changes in the positions of the N domains with respect to the hexameric ring during the ATP hydrolysis cycle. Nucleotide binding and hydrolysis experiments indicate that D2 inhibits nucleotide exchange by D1. The data suggest that the conversion of the chemical energy of ATP hydrolysis into mechanical work on substrates involves transmission of conformational changes generated by D2 through D1 to move N.
Davies
Jason M
JM
Department of Structural Biology, Stanford University School of Medicine, 299 Campus Drive West, Stanford, California 94305, USA.
Tsuruta
Hirotsugu
H
May
Andrew P
AP
Weis
William I
WI
D000251:Adenosine Triphosphatases; D000255:Adenosine Triphosphate / Q000737:chemistry / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000737:chemistry* / Q000378:metabolism; D006868:Hydrolysis; D008958:Models, Molecular; D017434:Protein Structure, Tertiary; D000074405:Valosin Containing Protein; D014961:X-Ray Diffraction
D018797:Cell Cycle Proteins; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D000074405:Valosin Containing Protein