Crystal structure of the N-terminal SH3 domain of mouse betaPIX, p21-activated kinase-interacting exchange factor.
The mouse betaPIX-SH3 domain, residues 8-63 of P21-activated kinase interacting exchange factor, has been characterized by X-ray diffraction. Crystals belonging to space group P3(2)21 diffracted to 2.0 A and the structure was phased by the single-wavelength anomalous diffraction method. The domain is a compact beta-barrel with an overall conformation similar to the general SH3 structure. The X-ray structure shows mouse betaPIX-SH3 domain binding the way in which the betaPIX characteristic amino acids do so for an unconventional ligand binding surface. This arrangement provides a rationale for the unusual ligand recognition motif exhibited by mouse betaPIX-SH3 domain. Comparison with another SH3/peptide complex shows that the recognition mode of the mouse betaPIX-SH3 domain should be very similar to the RXXK ligand binding mode. The unique large and planar hydrophobic pocket may contribute to the promiscuity of betaPIX-SH3 domain resulting in its multiple biological functions.
Li
Xiaofeng
X
Laboratory of Structural Biology, Tsinghua University, Beijing 100084, China.
Liu
Xueqi
X
Sun
Fei
F
Gao
Jia
J
Zhou
Hongwei
H
Gao
George F
GF
Bartlam
Mark
M
Rao
Zihe
Z
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D018797:Cell Cycle Proteins / Q000737:chemistry*; D018360:Crystallography, X-Ray; D019281:Dimerization; D020662:Guanine Nucleotide Exchange Factors / Q000737:chemistry*; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D064067:Rho Guanine Nucleotide Exchange Factors; D016415:Sequence Alignment; D018909:src Homology Domains
C576607:Arhgef7 protein, mouse; D018797:Cell Cycle Proteins; D020662:Guanine Nucleotide Exchange Factors; D064067:Rho Guanine Nucleotide Exchange Factors