8CNN

BeF3 Phospho-HRas GSA complex

Summary for 8CNN

• Entry DOI: 10.2210/pdb8cnn/pdb
• Descriptor: GTPase HRas, DI(HYDROXYETHYL)ETHER, ACETATE ION, ... (8 entities in total)
• Functional Keywords: small g protein, hydrolase, ground state analog
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 1
• Total formula weight: 20166.24

Authors

Baumann, P.,Jin, Y. (deposition date: 2023-02-23, release date: 2023-09-27, Last modification date: 2024-11-06)

Primary citation

Baumann, P.,Jin, Y.
Far-reaching effects of tyrosine64 phosphorylation on Ras revealed with BeF 3 - complexes.
Commun Chem, 7:19-19, 2024

PubMed Abstract: Tyrosine phosphorylation on Ras by Src kinase is known to uncouple Ras from upstream regulation and downstream communication. However, the mechanisms by which phosphorylation modulates these interactions have not been detailed. Here, the major mono-phosphorylation level on tyrosine64 is quantified by P NMR and mutagenesis. Crystal structures of unphosphorylated and tyrosine64-phosphorylated Ras in complex with a BeF ground state analogue reveal "closed" Ras conformations very different from those of the "open" conformations previously observed for non-hydrolysable GTP analogue structures of Ras. They deliver new mechanistic and conformational insights into intrinsic GTP hydrolysis. Phosphorylation of tyrosine64 delivers conformational changes distant from the active site, showing why phosphorylated Ras has reduced affinity to its downstream effector Raf. F NMR provides evidence for changes in the intrinsic GTPase and nucleotide exchange rate and identifies the concurrent presence of a major "closed" conformation alongside a minor yet functionally important "open" conformation at the ground state of Ras. This study expands the application of metal fluoride complexes in revealing major and minor conformational changes of dynamic and modified Ras proteins.

PubMed: 38297137
DOI: 10.1038/s42004-024-01105-6

Experimental method

X-RAY DIFFRACTION (1.48 Å)