Related Experiment Video
Updated: Jan 29, 2026
14:37
Modeling an Enzyme Active Site using Molecular Visualization Freeware
Published on: December 25, 2021
11.4K
Evolution of a new enzyme activity from the same motif fold
Petr G Leiman1, Ian J Molineux
1Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907, USA. leiman@purdue.edu
Molecular Microbiology
|April 25, 2008
Summary
Escherichia coli bacteriophage HK620 tailspike protein structure reveals similarities to related phages. This finding highlights how phages adapt protein folds for diverse host cell recognition and substrate binding.
Area of Science:
- Structural biology
- Microbiology
- Virology
Background:
- Bacteriophage HK620 tailspike is a host cell recognition protein.
- It cleaves the O18A1 type O antigen of Escherichia coli.
- Related phages P22 and Sf6 possess similar tailspikes.
Purpose of the Study:
- To determine the crystal structure of the HK620 tailspike.
- To compare its structure and organization with related phage tailspikes.
- To understand the mechanism of substrate recognition.
Main Methods:
- X-ray crystallography was used to determine the structure of the HK620 tailspike.
- Structures were determined in both apo and substrate-bound forms.
- Comparative structural analysis was performed with P22 and Sf6 tailspikes.
Main Results:
- The HK620 tailspike shares fold and organization similarities with P22 and Sf6 tailspikes despite lacking sequence similarity.
- The substrate-binding site in HK620 and P22 tailspikes is intrasubunit.
- The substrate-binding site in Sf6 tailspike is intersubunit.
Conclusions:
- Phage tailspikes can utilize similar protein folds for distinct substrate recognition mechanisms.
- Structural insights into HK620 tailspike provide a basis for understanding phage-host interactions.
- Adaptability of protein folds allows phages to evolve diverse substrate specificities.
Related Concept Videos
02:55The Evidence for Evolution
48.0K
Genetic variations accumulating within populations over generations give rise to biological evolution. Evolutionary changes can result in the formation of novel varieties and entire new species. These changes are responsible for the diverse forms of life inhabiting the planet. The evidence for evolution suggests that all living organisms descended from common ancestors.
48.0K
01:13Enzymes and Activation Energy
23.5K
The activation energy (or free energy of activation), abbreviated as Ea, is the small amount of energy input necessary for all chemical reactions to occur. During chemical reactions, certain chemical bonds break, and new ones form. For example, when a glucose molecule breaks down, bonds between the molecule's carbon atoms break. Since these are energy-storing bonds, they release energy when broken. However, the molecule must be somewhat contorted to get into a state that allows the bonds to...
23.5K
01:54Convergent Evolution
32.8K
Evolution shapes the features of organisms over time, ensuring that they are suited for the environments in which they live. Sometimes, selection pressure leads to the rise of similar but unrelated adaptations in organisms with no recent common ancestors, a process known as convergent evolution.
32.8K
01:22Protein Folding
127.2K
Overview
127.2K
01:25Protein Folding
11.4K
Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation, critical to its biological function. Interactions between its constituent amino acids guide protein folding, and hence the protein structure is primarily dependent on its amino acid sequence.
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
11.4K
02:34Enzymes
94.6K
Inside living organisms, enzymes act as catalysts for many biochemical reactions involved in cellular metabolism. The role of enzymes is to reduce the activation energies of biochemical reactions by forming complexes with its substrates. The lowering of activation energies favor an increase in the rates of biochemical reactions.
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
94.6K