title: 1H and 15N assignments and secondary structure of the PI3K SH3 domain.
abstract: The sequential 1H and 15N assignments of the SH3 domain of human phosphatidyl inositol 3'-kinase (PI3K) were determined by a combination of homonuclear and heteronuclear NMR experiments. With the exception of several protons belonging to lysine and proline residues, all proton and proton-bearing amide nitrogen resonances were assigned. Based on the sequential nuclear Overhauser effects (NOEs), 3JNH-C alpha H coupling constants and locations of slowly exchanging amide protons, we determined that the secondary structures of the protein consists of six beta-strands, two beta-turns and four short helices. Additional long range NOEs indicate that these beta-strands form two antiparallel beta-sheets. The topology of secondary structural elements of the PI3K SH3 domain is similar to those of the SH3 domains from c-Src and alpha-spectrin, suggesting that the SH3 family has a common tertiary structural motif.
authors.affiliation: Department of Chemistry, Harvard University, Cambridge, MA 02138.
authors.forename: S
authors.initials: S
authors.lastname: Koyama
authors.forename: H
authors.initials: H
authors.lastname: Yu
authors.forename: D C
authors.initials: DC
authors.lastname: Dalgarno
authors.forename: T B
authors.initials: TB
authors.lastname: Shin
authors.forename: L D
authors.initials: LD
authors.lastname: Zydowsky
authors.forename: S L
authors.initials: SL
authors.lastname: Schreiber
mesh_terms: D000595:Amino Acid Sequence; D016391:Genes, src; D006801:Humans; D006859:Hydrogen; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009587:Nitrogen Isotopes; D019869:Phosphatidylinositol 3-Kinases; D010770:Phosphotransferases / Q000737:chemistry* / Q000235:genetics; D017433:Protein Structure, Secondary; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000737:chemistry* / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013049:Spectrin / Q000737:chemistry
chemical_list: D009587:Nitrogen Isotopes; D013049:Spectrin; D006859:Hydrogen; D010770:Phosphotransferases; D019869:Phosphatidylinositol 3-Kinases; D016392:Proto-Oncogene Proteins pp60(c-src)