How much of protein sequence space has been explored by life on Earth?
2008
Exploring Protein Sequence Space
publication
Evidence: moderate
Author Information
Author(s): David T.F. Dryden, Andrew R. Thomson, John H. White
Primary Institution: School of Chemistry, University of Edinburgh
Hypothesis
How much of protein sequence space has been explored by life on Earth?
Conclusion
It is plausible that all functional protein sequence space has been explored during the evolution of life on Earth.
Supporting Evidence
- Estimates suggest that bacteria alone could have explored 4×10^43 different amino acid sequences.
- Most sequences have been tried and are useful in some way, indicating many possible routes to obtain proteins with desirable functions.
Takeaway
Scientists think that life on Earth has tried out almost all possible protein sequences, not just a tiny fraction.
Methodology
The study estimates the number of unique amino acid sequences produced since the origin of life using upper and lower limit calculations.
Limitations
The estimates are based on several assumptions that may not hold true for all organisms.
Digital Object Identifier (DOI)
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