A phosphoryl transfer intermediate in the GTPase reaction of Ras in complex with its GTPase-activating protein
| Autor: | Marco Blessenohl, Alfred Wittinghofer, Yan Suveyzdis, Klaus Gerwert, Carsten Kötting, Roger S. Goody |
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| Rok vydání: | 2006 |
| Předmět: |
Models
Molecular Eclipsed conformation Binding Sites Multidisciplinary Molecular Structure GTPase-activating protein GTP' Protein Conformation Stereochemistry Hydrogen Bonding GTPase Guanosine triphosphate Phosphates Enzyme Activation Enzyme activator chemistry.chemical_compound Protein structure chemistry ras GTPase-Activating Proteins Spectroscopy Fourier Transform Infrared Physical Sciences ras Proteins Guanosine Triphosphate Protons Binding site |
| Zdroj: | Proceedings of the National Academy of Sciences. 103:13911-13916 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.0604128103 |
| Popis: | The hydrolysis of nucleoside triphosphates by enzymes is used as a regulation mechanism in key biological processes. Here, the GTP hydrolysis of the protein complex of Ras with its GTPase-activating protein is monitored at atomic resolution in a noncrystalline state by time-resolved FTIR spectroscopy. At 900 ms, after the attack of water at the γ-phosphate, there appears a H2PO4−intermediate that is shown to be hydrogen-bonded in an eclipsed conformation to the β-phosphate of GDP. The H2PO4−intermediate is in a position where it can either reform GTP or be released from the protein in 7 s in the rate-limiting step of the GTPase reaction. We propose that such an intermediate also occurs in other GTPases and ATPases. |
| Databáze: | OpenAIRE |
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