Protein structure determination, NMR and computational techniques
The research in the Wagner laboratory is focused on protein
structure, dynamics and stability, and on the relation of these to protein
function. Of particular interest are studies of receptor-ligand interactions
in systems of pharmaceutical interest. NMR and computational techniques
are the main tools used to address these problems. We are interested
in how internal motions are related to protein function, and what the impact
of mobility on receptor surfaces is on ligand binding. As one step
in addressing this problem, we have developed strategies to map spectral
density functions of rotational diffusive motions of N-H or C-H bond vectors
by measuring a set of heteronuclear relaxation parameters. This research
includes the following topics:
T-cell adhesion molecules: We seek to understand
the specificity of the interactions of T-cell receptor molecules with their
ligands. To this end, we are working on the solution structure of the human
T-cell adhesion glycoprotein CD2 and its counter receptor CD58. One of
the goals of this project is to solve the complex between the adhesion
domains of CD2 and CD58. We are also working on CD4-ligand interactions
and on the structure of a single chain T-cell antigen receptor.
Translation initiation: Initiation of translation involves binding of the translation initiation factor eIF-4E to the messenger RNA cap. This process is regulated by phosphorylation as well as binding of the inhibitory 4E-binding protein (4E-BP). For example, phosphorylation of 4E-BP leads to dissociation of the eIF-4E/4E-BP complex and thus to translation initiation. We are examining the structure of eIF-4E in complex with cap analogs as well as ternary complexes with 4E-BP or fragments of eIF-4G. We are also working on other factors involved in eukaryotic translation initiation, such as eIF1 and eIF1A, which facilitate the scanning of the preinitiation complex to reach the initiation codon.
Proteins involved in transcription and transcriptional activaton. We are interested in the structural basis of transcriptional activation. Current studies are focused on a universal component of the human RNA polymerases and a HAT domain (tetrahymena Gcn5).
ada-protein: In collaboration with G. Verdine (Dept. of Chemistry), we are studying fragments of ada, a methyl DNA transferase from E.coli. The 3D structure, DNA binding and the mechanism of the methyl transfer are under investigation. We have already solved the structure of an N-terminal 10 kD fragment that contains the repair function. At present, we are working on the complex of a 15kD fragment of ada with DNA.
Apoptosis proteins: We are interested in protein-protein interactions that are relevant for apoptosis. We are working on the structure of the prodomain of RAIDD and are interested in its interaction with the prodomain of ICH-1 (caspase-2). We are also interested in structure and function of the BID protein that is relevant for promoting mitochondrial damage in apoptosis.
Selected publications:
H. Matsuo, H. Li, A. M. McGuire, C. M. Fletcher, A.-C.
Gingras, N. Sonenberg and G. Wagner: Structure of Translation Factor eIF4E
Bound to m7GDP and Interaction with 4E-Binding Protein. Nature Structural
Biol., 4, 717-724 (1997).
J.J. Chou, H. Matsuo, H. Duan, G. Wagner: Solution Structure of the RAIDD CARD Domain and model for CARD/CARD interaction in caspase-2 and caspase-9 recruitment, Cell, 94, 171-180 (1998).
J. J. Chou, H. Li, G. S. Salvesen, J. Yuan, and G. Wagner
Solution Structure of BID, an Intracellular Amplifier of Apoptotic Signaling.,
Cell, 96, 615-624 (1999).