Cryo-EM structure of the prohibitin complex in open conformation
Sixing Hong1, Zeyuan Guan1, Liying Zhang1
1National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan 430070, China.
Summary
The prohibitin complex, formed by Prohibitin 1 (PHB1) and Prohibitin 2 (PHB2), has a bell-like cage structure. This structure helps organize mitochondrial inner membrane proteins and lipids, maintaining cellular homeostasis.
Area of Science:
- Mitochondrial biology
- Structural biology
- Cellular homeostasis
Background:
- Prohibitin 1 (PHB1) and Prohibitin 2 (PHB2) form a complex in the mitochondrial inner membrane.
- This complex is crucial for cellular metabolism and homeostasis.
- The precise architecture of the prohibitin complex is largely unknown.
Purpose of the Study:
- To determine the high-resolution structure of the prohibitin complex.
- To elucidate the architectural basis for the prohibitin complex's function.
Main Methods:
- Cryo-electron microscopy (cryo-EM) was used to determine the structure.
- High-resolution structural analysis at 2.8 Å.
Main Results:
- The prohibitin complex forms a bell-like cage structure composed of 11 PHB1-PHB2 heterodimers.
- The cage has a stable lid responsible for complex assembly and a flexible wall with openings.
- The structure reveals a compartment facing the intermembrane space and channels for lipid and protein exchange.
Conclusions:
- The determined structure provides a detailed understanding of the prohibitin complex's organization.
- The findings offer insights into the scaffold role of the prohibitin complex in organizing mitochondrial inner membrane proteins and lipids.
- This structural basis aids in understanding cellular metabolism and homeostasis maintenance.
More Related Videos
Related Concept Videos
01:28Cryo-electron Microscopy
4.2K
Conventional electron microscopy (EM) involves dehydration, fixation, and staining of biological samples, which distorts the native state of biological molecules and results in several artifacts. Also, the high-energy electron beam damages the sample and makes it difficult to obtain high-resolution images. These issues can be addressed using cryo-EM, which uses frozen samples and gentler electron beams. The technique was developed by Jacques Dubochet, Joachim Frank, and Richard Henderson, for...
4.2K
03:00Molecular Chaperones and Protein Folding
19.6K
The native conformation of a protein is formed by interactions between the side chains of its constituent amino acids. When the amino acids cannot form these interactions, the protein cannot fold by itself and needs chaperones. Notably, chaperones do not relay any additional information required for the folding of polypeptides; the native conformation of a protein is determined solely by its amino acid sequence. Chaperones catalyze protein folding without being a part of the folded protein.
The...
The...
19.6K
01:21Structure of Porins
3.8K
Mitochondria, chloroplasts, and gram-negative bacteria have transmembrane, beta-barrel proteins called porins to mediate the free diffusion of ions and metabolites across the membrane. Mitochondrial porin precursors contain conserved amino acid sequences called beta signals at their C-terminal. Beta signals have a motif of PoXGXXHyXHy (Po-Polar, X-Any amino acid, G-Glycine, Hy-LargeHydrophobic), which are crucial for precursor recognition to initiate precursor assembly. Beta-barrel...
3.8K
02:15Protein and Protein Structure
86.9K
Proteins are one of the most abundant organic molecules in living systems and have the most diverse range of functions of all macromolecules. Proteins may be structural, regulatory, contractile, or protective. They may serve in transport, storage, or membranes; or they may be toxins or enzymes. Their structures, like their functions, vary greatly. They are all, however, amino acid polymers arranged in a linear sequence.
A protein's shape is critical to its function. For example, an enzyme...
A protein's shape is critical to its function. For example, an enzyme...
86.9K