Related Experiment Video
Updated: Jun 21, 2026
06:45
Transmembrane Domain Oligomerization Propensity determined by ToxR Assay
Published on: May 26, 2011
Two-state allosteric behavior in a single-domain signaling protein
B F Volkman1, D Lipson, D E Wemmer
1National Magnetic Resonance Facility at Madison (NMRFAM), Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
Science (New York, N.Y.)
|March 27, 2001
Summary
Signaling protein NtrC activation correlates with microsecond dynamics. Phosphorylation shifts equilibrium between inactive and active conformations, revealing a dynamic population shift mechanism.
Area of Science:
- Biochemistry
- Molecular Biology
- Structural Biology
Background:
- Protein function is intrinsically linked to dynamic motions, not just static structures.
- Understanding the activation mechanisms of signaling proteins is crucial in molecular biology.
Purpose of the Study:
- To investigate the correlation between phosphorylation-driven activation of the signaling protein NtrC and its backbone dynamics.
- To characterize the motions of NtrC across different functional states.
Main Methods:
- Utilized nuclear magnetic resonance (NMR) relaxation techniques.
- Analyzed protein dynamics on the microsecond time scale.
- Examined NtrC in unphosphorylated (inactive), phosphorylated (active), and a partially active mutant states.
Main Results:
- A strong correlation was observed between NtrC phosphorylation-induced activation and microsecond time-scale backbone dynamics.
- Protein dynamics indicated an exchange between inactive and active conformations.
- Unphosphorylated NtrC exists as a mixture of both conformations, with phosphorylation favoring the active state.
Conclusions:
- Protein activation is driven by a dynamic population shift between pre-existing conformations.
- The mechanism of NtrC activation involves a conformational equilibrium shift upon phosphorylation.
- Microsecond dynamics are key to understanding the functional activation of signaling proteins like NtrC.
Related Concept Videos
01:28Yeast Signaling
Yeasts are single-celled organisms, but unlike bacteria, they are eukaryotes (cells with a nucleus). Cell signaling in yeast is similar to signaling in other eukaryotic cells. A ligand, such as a protein or a small molecule released from a yeast cell, attaches to a receptor on the cell surface. The binding stimulates second-messenger kinases to activate or inactivate transcription factors that further regulate gene expression. Many of the yeast intracellular signaling cascades have similar...
02:26Conservation of Protein Domains Over Different Proteins
Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms.
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
01:25Single-pass Transmembrane Proteins
Integral membrane proteins are tightly associated with the cell membrane and play a crucial role in cell communication, signaling, adhesion, and transport of the molecules. Some integral membrane proteins are present only in the membrane monolayer. For example, the enzyme fatty acid amide hydrolase is present in the cytoplasmic side of the membrane monolayer. In contrast, another type of integral membrane protein, also known as a transmembrane protein, spans across the membrane. Transmembrane...
01:46Nuclear Localization Signals and Import
Proteins targeted to the nucleus carry short stretches of amino acid sequences called the nuclear localization signal or NLS. Classical nuclear localization signals are of two types: monopartite and bipartite NLS. Monopartite classical NLS (cNLS) consists of a single cluster of 4-8 amino acids. Bipartite cNLS consists of two clusters of 2-3 amino acids and a 9-12 residue long proline-rich linker bridging the two clusters. Signal clusters are rich in positively charged amino acids such as...
01:26Insertion of Single-pass Transmembrane Proteins in the RER
Integral membrane proteins are proteins adhered to the lipid bilayer of a cell organelle or membrane. They can be of two types: transmembrane integral proteins that span the lipid bilayer and monotopic proteins that are attached to either side of the membrane but do not pass through it.
Integral transmembrane proteins possess transmembrane and extra membrane domains. The transmembrane domains are primarily made of 20-25 hydrophobic amino acids arranged in a helical secondary confirmation. These...
Integral transmembrane proteins possess transmembrane and extra membrane domains. The transmembrane domains are primarily made of 20-25 hydrophobic amino acids arranged in a helical secondary confirmation. These...
01:30Assembly of Signaling Complexes
Multiprotein signaling complexes are formed in a dynamic process involving protein-protein interactions at the cytoplasmic domain of transmembrane receptors or enzymatic and non-enzymatic proteins associated with the receptor. These complexes ensure the activation and propagation of intracellular signals that regulate cell functions.
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...