Related Experiment Video
Updated: Aug 7, 2026
11:42
Iterative Optimization of DNA Duplexes for Crystallization of SeqA-DNA Complexes
Published on: November 1, 2012
The euryarchaeota, nature's medium for engineering of single-stranded DNA-binding proteins
Justin B Robbins1, Mary C McKinney, Claudia E Guzman
1Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
The Journal of Biological Chemistry
|January 27, 2005
Summary
Archaea extensively utilize the oligonucleotide/oligosaccharide binding (OB) fold to create diverse single-stranded DNA-binding proteins, some found even in humans, revealing significant evolutionary links.
Area of Science:
- Molecular Biology
- Biochemistry
- Evolutionary Biology
Background:
- Single-stranded DNA-binding proteins (SSBs) are crucial for DNA metabolism.
- Bacterial SSBs use one OB fold, while eukaryotic SSBs are a complex of three proteins.
Purpose of the Study:
- Investigate the diversity and evolution of SSBs in Euryarchaeota.
- Explore the functional implications of different SSB architectures.
Main Methods:
- Comparative genomics
- Protein engineering (deletion mutants, chimeras)
- Biophysical studies (DNA binding modes)
- Domain analysis
Main Results:
- Euryarchaeota exhibit a high diversity of SSBs, often featuring two OB folds and a zinc finger domain.
- SSB orthologs display distinct DNA binding modes (wrapping and stretching).
- A single OB fold SSB in *Ferroplasma acidarmanus* (FacRPA2) uses the wrapping mode, similar to Crenarchaeal proteins.
- Genes for simple SSBs are found across all domains of life, including humans.
Conclusions:
- Gene duplication and recombination drive SSB innovation in Archaea.
- The simplest SSB forms have ancient origins and broad evolutionary distribution.
- Archaeal SSBs offer insights into the evolution of DNA-binding proteins in eukaryotes.
Related Concept Videos
01:03Single-Strand DNA Binding Proteins
For successful DNA replication, the unwinding of double-stranded DNA must be accompanied by stabilization and protection of the separated single strands of the DNA. This crucial task is performed by single-strand DNA-binding (SSB) proteins. They bind to the DNA in a sequence-independent manner, which means that the nitrogenous bases of the DNA need not be present in a specific order for binding of SSB proteins to it. The binding of SSB proteins straightens single-stranded DNA (ssDNA) and makes...
01:32Replication in Prokaryotes
DNA replication has three main steps: initiation, elongation, and termination. Replication in prokaryotes begins when initiator proteins bind to the single origin of replication (ori) on the cell's circular chromosome. Replication then proceeds around the entire circle of the chromosome in each direction from the two replication forks, resulting in two DNA molecules.
Many Proteins Work Together to Replicate the Chromosome
Replication is coordinated and carried out by a host of specialized...
Many Proteins Work Together to Replicate the Chromosome
Replication is coordinated and carried out by a host of specialized...
01:24Nucleoid
The nucleoid represents a structurally and functionally distinct region within prokaryotic cells, where the cell's DNA and associated proteins are housed. Unlike eukaryotic cells, prokaryotes lack a membrane-bound nucleus, and the nucleoid facilitates the organization and accessibility of the genetic material within this constraint. The DNA in most bacteria and archaea exists as a single, circular, double-stranded molecule that is highly compacted through supercoiling and interactions with...
01:30Diversity of Archaea I
Archaea, a domain of single-celled microorganisms, are classified into five major phyla based on genetic and biochemical characteristics: Euryarchaeota, Crenarchaeota, Thaumarchaeota, Korarchaeota, and Nanoarchaeota. Among these, the phylum Euryarchaeota is notable for its remarkable diversity in morphology, metabolism, and ecological adaptations.Morphological and Metabolic DiversityMembers of Euryarchaeota exhibit a variety of cellular shapes, including rods and cocci. Their metabolic pathways...
01:27Diversity of Archaea III
Crenarchaeota, a prominent phylum of Archaea, is remarkable for its ability to thrive in extreme environments characterized by high temperatures and acidity. These microorganisms inhabit sulfuric hot springs, volcanic systems, and submarine hydrothermal vents, where temperatures often exceed 100°C. The unique adaptations of Crenarchaeota not only allow survival under such extreme conditions but also provide insights into the mechanisms of life in primordial Earth-like environments.Morphological...
01:29Diversity of Archaea IV
Hyperthermophilic archaea are a group of extremophiles thriving at temperatures above 80°C, often in hydrothermal vents and volcanic soils where conditions surpass the boiling point of water. At such temperatures, proteins, membranes, and DNA in most organisms degrade, but hyperthermophiles have evolved remarkable adaptations to maintain stability and function.Unique Cellular FeaturesHyperthermophilic membranes are composed of a monolayer of biphytanyl tetraether lipids, which resist thermal...