In:
Frontiers in Molecular Biosciences, Frontiers Media SA, Vol. 9 ( 2022-4-8)
Abstract:
The Ras-specific guanine nucleotide exchange factors Son of Sevenless (SOS) regulates Ras activation by converting inactive GDP-bound to active GTP-bound states. The catalytic activity of Ras is further allosterically regulated by GTP−Ras bound to a distal site through a positive feedback loop. To address the mechanism underlying the long-range allosteric activation of the catalytic K-Ras4B by an additional allosteric GTP–Ras through SOS, we employed molecular dynamics simulation of the K-Ras4B G13D •SOS cat complex with and without an allosteric GTP-bound K-Ras4B G13D . We found that the binding of an allosteric GTP−K-Ras4B G13D enhanced the affinity between the catalytic K-Ras4B G13D and SOS cat , forming a more stable conformational state. The peeling away of the switch I from the nucleotide binding site facilitated the dissociation of GDP, thereby contributing to the increased nucleotide exchange rate. The community networks further showed stronger edge connection upon allosteric GTP−K-Ras4B G13D binding, which represented an increased interaction between catalytic K-Ras4B G13D and SOS cat . Moreover, GTP−K-Ras4B G13D binding transmitted allosteric signaling pathways though the Cdc25 domain of SOS that enhanced the allosteric regulatory from the K-Ras4B G13D allosteric site to the catalytic site. This study may provide an in-depth mechanism for abnormal activation and allosteric regulation of K-Ras4B G13D .
Type of Medium:
Online Resource
ISSN:
2296-889X
DOI:
10.3389/fmolb.2022.860962
Language:
Unknown
Publisher:
Frontiers Media SA
Publication Date:
2022
detail.hit.zdb_id:
2814330-9
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