AbstractsBiology & Animal Science

Intracellular signalling cascades are mediated by a plethora of receptors, enzymes, adaptors and small molecules. The Protein Tyrosine Phosphatase (PTP) Shp2 is a highly conserved enzyme involved in a myriad of cellular processes including growth, differentiation and apoptosis. Shp2 is multi-domain protein composed of two SH2 domains in tandem, a PTP catalytic domain and a C-terminal tail containing multiple phosphorylation sites and a proline-rich region. The majority of biophysical research has utilised X-ray crystallography to study interactions and effects of mutations at the structural level. To gain a further understanding of Shp2 ligand binding and perturbations caused by disease relevant mutations, a structural investigation was performed with Nuclear Magnetic Resonance (NMR) spectroscopy and Small-angle X-ray Scattering (SAXS) in solution. The NMR signals from the backbone of both SH2 domains were assigned and residue-level interactions and differential SH2 domain specificities with peptides from the novel receptor G6b-B were delineated. In addition, the E76K point mutation that causes Noonan Syndrome and leukaemia was found to have increased conformational dynamics, the first experimental evidence of this phenomenon at the structural level.