Solution structure of the tandem Src homology 3 domains of p47phox in an autoinhibited form.
The phagocyte NADPH oxidase is a multisubunit enzyme responsible for the generation of superoxide anions (O(2).) that kill invading microorganisms. p47(phox) is a cytosolic subunit of the phagocyte NADPH oxidase, which plays a crucial role in the assembly of the activated NADPH oxidase complex. The molecular shapes of the p47(phox) tandem SH3 domains either with or without a polybasic/autoinhibitory region (PBR/AIR) at the C terminus were studied using small angle x-ray scattering. The tandem SH3 domains with PBR/AIR formed a compact globular structure, whereas the tandem SH3 domains lacking the PBR/AIR formed an elongated structure. Alignment anisotropy analysis by NMR based on the residual dipolar couplings revealed that the tandem SH3 domains with PBR/AIR were in good agreement with a globular module corresponding to the split half of the intertwisted dimer in crystalline state. The structure of the globular module was elucidated to represent a solution structure of the tandem SH3 domain in the autoinhibited form, where the PBR/AIR bundled the tandem SH3 domains and the linker forming a closed structure. Once PBR/AIR is released by phosphorylation, rearrangements of the SH3 domains may occur, forming an open structure that binds to the cytoplasmic proline-rich region of membrane-bound p22(phox).
Yuzawa
Satoru
S
Department of Structural Biology, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan.
Ogura
Kenji
K
Horiuchi
Masataka
M
Suzuki
Nobuo N
NN
Fujioka
Yuko
Y
Kataoka
Mikio
M
Sumimoto
Hideki
H
Inagaki
Fuyuhiko
F
D019281:Dimerization; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D010750:Phosphoproteins / Q000737:chemistry* / Q000378:metabolism; D017433:Protein Structure, Secondary; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D018909:src Homology Domains
D010750:Phosphoproteins; D021122:Protein Subunits