title: Crystal structure of the N-terminal SH3 domain of mouse betaPIX, p21-activated kinase-interacting exchange factor.
abstract: 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.
authors.affiliation: Laboratory of Structural Biology, Tsinghua University, Beijing 100084, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Li
authors.forename: Xueqi
authors.initials: X
authors.lastname: Liu
authors.forename: Fei
authors.initials: F
authors.lastname: Sun
authors.forename: Jia
authors.initials: J
authors.lastname: Gao
authors.forename: Hongwei
authors.initials: H
authors.lastname: Zhou
authors.forename: George F
authors.initials: GF
authors.lastname: Gao
authors.forename: Mark
authors.initials: M
authors.lastname: Bartlam
authors.forename: Zihe
authors.initials: Z
authors.lastname: Rao
mesh_terms: 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
chemical_list: C576607:Arhgef7 protein, mouse; D018797:Cell Cycle Proteins; D020662:Guanine Nucleotide Exchange Factors; D064067:Rho Guanine Nucleotide Exchange Factors