Related Experiment Video
Updated: Aug 16, 2026
09:35
Microcrystallography of Protein Crystals and In Cellulo Diffraction
Published on: July 21, 2017
Crystal lattice as biological phenotype for insect viruses
Karin Anduleit1, Geoff Sutton, Jonathan M Diprose
1Division of Structural Biology, The Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK.
Protein Science : a Publication of the Protein Society
|September 13, 2005
Summary
Insect viruses form protective protein crystals called polyhedra. Remarkably, two distinct virus families share identical crystal structures, suggesting this lattice is crucial for viral protection.
Area of Science:
- Virology
- Structural Biology
- Biophysics
Background:
- Insect viruses often survive by forming crystalline polyhedra.
- These polyhedra are primarily composed of a single polyhedrin protein.
- The polyhedrin protein's structure is key to forming these protective crystals.
Purpose of the Study:
- To investigate the structural characteristics of polyhedra formed by different insect virus families.
- To determine if there is a conserved structural basis for polyhedra formation despite variations in the polyhedrin protein sequence.
- To understand the functional implications of conserved polyhedra crystal lattice structures.
Main Methods:
- Comparative analysis of polyhedra crystal structures from different insect virus families.
- Determination of cell constants and lattice type for polyhedra.
- Bioinformatic analysis to assess sequence similarity of the encoded polyhedrin proteins.
Main Results:
- Two distinct insect virus families produce polyhedra with identical cell constants.
- Both virus families form polyhedra with a body-centered cubic lattice.
- The viral polyhedrin proteins show no significant sequence similarity.
Conclusions:
- The identical crystal lattice suggests a strong evolutionary selection for this structure.
- The conserved lattice is likely critical for the efficient packaging and long-term protection of insect viruses.
- This structural conservation highlights a fundamental principle in viral capsid formation and survival strategies.
Related Concept Videos
00:56Viral Structure
Viruses are extraordinarily diverse in shape and size, but they all have several structural features in common. All viruses have a core that contains a DNA- or RNA-based genome. The core is surrounded by a protective coat of proteins called the capsid. The capsid is composed of subunits called capsomeres. The capsid and genome-containing core are together known as the nucleocapsid.
01:23The Antiviral System of Bacteria and Archaea: CRISPR
CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats is a adaptive immune system found in bacteria and archaea that protects against viral infections. This system enables prokaryotic cells to identify, remember, and neutralize foreign genetic elements, primarily bacteriophages, by storing fragments of the invader’s DNA as a genetic memory.The CRISPR immune response begins during an initial infection. Cas (CRISPR-associated) proteins play a central role in this defense.
01:28Introduction to Virus
Viruses are unique biological entities that blur the boundary between living and non-living systems. Although they lack cellular structure and metabolic processes, they can exhibit characteristics of life when infecting a host. Their defining feature is a nucleic acid core, composed of either DNA or RNA, encapsulated within a protein coat called a capsid. This simple structure allows them to invade host cells and use their machinery for replication efficiently.Viral Structure and...
01:30Lytic Cycle of Bacteriophages
Bacteriophages, also known as phages, are specialized viruses that infect bacteria. A key characteristic of phages is their distinctive “head-tail” morphology. A phage begins the infection process (i.e., lytic cycle) by attaching to the outside of a bacterial cell. Attachment is accomplished via proteins in the phage tail that bind to specific receptor proteins on the outer surface of the bacterium. The tail injects the phage’s DNA genome into the bacterial cytoplasm. In the lytic replication...
01:26Size and Structure of Viral Genomes
Viral genomes exhibit remarkable diversity in size, structure, and composition, influencing their replication strategies and interactions with host cells. These genomes consist of either DNA or RNA and may be linear or circular. Additionally, they can be single-stranded or double-stranded, with each configuration affecting how the virus propagates within a host. RNA viruses, for instance, generally have smaller genomes than DNA viruses, a factor that contributes to their high mutation rates and...
00:50What are Viruses?
Overview