A novel ATP-dependent conformation in p97 N-D1 fragment revealed by crystal structures of disease-related mutants.
Mutations in p97, a major cytosolic AAA (ATPases associated with a variety of cellular activities) chaperone, cause inclusion body myopathy associated with Paget's disease of the bone and frontotemporal dementia (IBMPFD). IBMPFD mutants have single amino-acid substitutions at the interface between the N-terminal domain (N-domain) and the adjacent AAA domain (D1), resulting in a reduced affinity for ADP. The structures of p97 N-D1 fragments bearing IBMPFD mutations adopt an atypical N-domain conformation in the presence of Mg(2+).ATPgammaS, which is reversible by ADP, showing for the first time the nucleotide-dependent conformational change of the N-domain. The transition from the ADP- to the ATPgammaS-bound state is accompanied by a loop-to-helix conversion in the N-D1 linker and by an apparent re-ordering in the N-terminal region of p97. X-ray scattering experiments suggest that wild-type p97 subunits undergo a similar nucleotide-dependent N-domain conformational change. We propose that IBMPFD mutations alter the timing of the transition between nucleotide states by destabilizing the ADP-bound form and consequently interfere with the interactions between the N-domains and their substrates.
Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
Wai Kwan
WK
Tang
Dongyang
D
Li
Chou-chi
CC
Li
Lothar
L
Esser
Renming
R
Dai
Liang
L
Guo
Di
D
Xia
D000244:Adenosine Diphosphate / Q000737:chemistry / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D018797:Cell Cycle Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D018360:Crystallography, X-Ray; D006801:Humans; D008274:Magnesium / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D010001:Osteitis Deformans / Q000235:genetics*; D017354:Point Mutation; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D013379:Substrate Specificity; D000074405:Valosin Containing Protein
D018797:Cell Cycle Proteins; C022571:adenosine 5'-O-(3-thiotriphosphate); D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; C000614178:VCP protein, human; D000074405:Valosin Containing Protein; D008274:Magnesium