Publications by authors named "Alicia Y Volmar"
HRas, KRas, and NRas are GTPases with a common set of effectors that control many cell-signaling pathways, including proliferation through Raf kinase. Their G-domains are nearly identical in sequence, with a few isoform-specific residues that have an effect on dynamics and biochemical properties. Here, we use accelerated molecular dynamics (aMD) simulations consistent with solution x-ray scattering experiments to elucidate mechanisms through which isoform-specific residues associated with each Ras isoform affects functionally important regions connected to the active site.
View Article and Find Full Text PDFTitration of ionizable groups in proteins using multiple neutron data sets from a single crystal: application to the small GTPase Ras.
Acta Crystallogr F Struct Biol Commun
February 2019
Article Synopsis
- Neutron protein crystallography (NPC) is a technique that determines 3D protein structures, focusing on hydrogen atom positions and helping to clarify complex biochemical reactions.
- Although NPC offers advantages like no radiation damage to crystals, it requires large single crystals due to low neutron beam flux.
- A study using NPC on the GTPase Ras at different pD levels demonstrated its potential for examining active site behavior and allosteric communication networks, particularly through key residues like Cys118 and specific tyrosines.
Structures of wild-type K-Ras from crystals obtained in the presence of guanosine triphosphate (GTP) or its analogs have remained elusive. Of the K-Ras mutants, only K-RasG12D and K-RasQ61H are available in the PDB representing the activated form of the GTPase not in complex with other proteins. We present the crystal structure of wild-type K-Ras bound to the GTP analog GppCHp, with K-Ras in the state 1 conformation.
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