1H and 15N assignments and secondary structure of the PI3K SH3 domain.
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.
Koyama
S
S
Department of Chemistry, Harvard University, Cambridge, MA 02138.
Yu
H
H
Dalgarno
D C
DC
Shin
T B
TB
Zydowsky
L D
LD
Schreiber
S L
SL
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
D009587:Nitrogen Isotopes; D013049:Spectrin; D006859:Hydrogen; D010770:Phosphotransferases; D019869:Phosphatidylinositol 3-Kinases; D016392:Proto-Oncogene Proteins pp60(c-src)