Related Experiment Video
Updated: Jun 21, 2026
06:45
Transmembrane Domain Oligomerization Propensity determined by ToxR Assay
Published on: May 26, 2011
Structural determinants of transmembrane helical proteins.
Susan E Harrington1, Nir Ben-Tal
1Department of Biochemistry, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Israel.
Structure (London, England : 1993)
|August 15, 2009
Summary
Researchers discovered that five specific interhelical interactions precisely control transmembrane protein structure. This finding offers new insights into protein construction, stability, and folding prediction.
Area of Science:
- Biochemistry
- Structural Biology
- Computational Biology
Background:
- Transmembrane helical proteins are crucial for cellular functions.
- Understanding their native states and conformational dynamics is essential.
Purpose of the Study:
- To identify a key structural feature governing transmembrane protein stability.
- To propose a novel approach for understanding protein construction and native states.
Main Methods:
- Iterative reassembly of helix bundles from 15 diverse proteins.
- Utilizing five specific interhelical interactions: hydrogen bonds, aromatic interactions, salt bridges, and two packing motifs.
- Employing generic interaction geometries and individual helix backbone conformations.
Main Results:
- Demonstrated that these five interactions precisely determine transmembrane helix packing.
- Rebuilt protein structures showed an average C-alpha root-mean-square deviation of 1.03 Å from native structures.
- The five interactions effectively constrain the conformational space of these proteins.
Conclusions:
- The identified structural feature provides a new framework for understanding protein stability.
- Findings have implications for protein folding, structure prediction, modeling, and design.
- This work advances the predictive power of computational protein studies.
Related Concept Videos
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...
01:09Multi-pass Transmembrane Proteins and β-barrels
In multi-pass transmembrane proteins, the polypeptide chain crosses the membrane more than once. The transmembrane polypeptide chain either forms an α-helix or β-strand structure. α-Helix containing multi-pass transmembrane proteins are ubiquitous, whereas β-strand containing ones are mainly found in gram-negative bacteria, mitochondria, and chloroplasts.
α-Helix containing multi-pass transmembrane proteins
Multi-pass transmembrane proteins such as G-protein-linked receptors (GPCRs) and...
α-Helix containing multi-pass transmembrane proteins
Multi-pass transmembrane proteins such as G-protein-linked receptors (GPCRs) and...
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...
01:29Insertion of Multi-pass Transmembrane Proteins in the RER
The rough ER membrane synthesizes, assembles, and embeds transmembrane proteins in diverse topologies. These proteins function as transporters or channels and can remain in the ER membrane or are sent to the Golgi complex, lysosome, and cell membrane.
The multipass transmembrane proteins are the type IV integral membrane proteins with multiple topogenic sequences determining their spatial arrangement in the ER membrane. Nearly all multipass proteins lack a cleavable signal sequence and use...
The multipass transmembrane proteins are the type IV integral membrane proteins with multiple topogenic sequences determining their spatial arrangement in the ER membrane. Nearly all multipass proteins lack a cleavable signal sequence and use...
01:16Introduction to Membrane Proteins
The cell membrane, or plasma membrane, is an ever-changing landscape. It is described as a fluid mosaic where various macromolecules are embedded in the phospholipid bilayer. Among the macromolecules are proteins. The protein content varies across cell types. For example, mitochondrial inner membranes contain ~76% protein content, while myelin contains ~18% protein content. Individual cells contain many types of membrane proteins—red blood cells contain over 50—and different cell types have...
01:34Protein Transport into the Inner Mitochondrial Membrane
Nuclear encoded mitochondrial precursors are imported to the inner membrane in a multistep process involving two separate translocons, TIM22 and TIM23. TIM23 is a cation-selective pore that remains closed by the N terminal segment of the protein. Negative charges on the TIM23 act as a receptor for the incoming precursor, pulling the positively charged matrix-targeting sequence for peptide insertion and translocation.
Transport of mitochondrial precursors across the TIM23 channel is driven by...
Transport of mitochondrial precursors across the TIM23 channel is driven by...