Skip to main content
Log in

Reconstruction and Characterization of Thermally Stable and Catalytically Active Proteins Comprising an Alphabet of ~ 13 Amino Acids

  • Original Article
  • Published:
Journal of Molecular Evolution Aims and scope Submit manuscript

Abstract

While extant organisms synthesize proteins using approximately 20 kinds of genetically coded amino acids, the earliest protein synthesis system is likely to have been much simpler, utilizing a reduced set of amino acids. However, which types of building blocks were involved in primordial protein synthesis remains unclear. Herein, we reconstructed three convergent sequences of an ancestral nucleoside diphosphate kinase, each comprising a 10 amino acid “alphabet,” and found that two of these variants folded into soluble and stable tertiary structures. Therefore, an alphabet consisting of 10 amino acids contains sufficient information for creating stable proteins. Furthermore, re-incorporation of a few more amino acid types into the active site of the 10 amino acid variants improved the catalytic activity, although the specific activity was not as high as that of extant proteins. Collectively, our results provide experimental support for the idea that robust protein scaffolds can be built with a subset of the current 20 amino acids that might have existed abundantly in the prebiotic environment, while the other amino acids, especially those with functional sidechains, evolved to contribute to efficient enzyme catalysis.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3

Similar content being viewed by others

References

Download references

Acknowledgements

This work was supported by JSPS KAKENHI (Grant Numbers 17H03716 and 19K21903) and the Astrobiology Center Program of National Institutes of Natural Sciences (NINS) (Grant Number AB312004).

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Satoshi Akanuma.

Additional information

Handling Editor: Aaron Goldman.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Supplementary file1 (PDF 664 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Kimura, M., Akanuma, S. Reconstruction and Characterization of Thermally Stable and Catalytically Active Proteins Comprising an Alphabet of ~ 13 Amino Acids. J Mol Evol 88, 372–381 (2020). https://doi.org/10.1007/s00239-020-09938-0

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00239-020-09938-0

Keywords

Navigation