Inferred ancestry of scytonemin biosynthesis proteins in cyanobacteria indicates a response to Paleoproterozoic oxygenation
Name
Geobiology - 2022 - Tamre - Inferred ancestry of scytonemin biosynthesis proteins in cyanobacteria indicates a response to.pdf
Description
Published version
Size
2.82 MB
Format
Adobe PDF
Checksum (MD5)
2ccfedf0758a8561f87d882193a8a861
Author(s)
Tamre, Erik
Fournier, Gregory P
Date Issued
July 18, 2022
Journal
Geobiology
Publisher
Wiley
Citation
Tamre, Erik and Fournier, Gregory P. 2022. "Inferred ancestry of scytonemin biosynthesis proteins in cyanobacteria indicates a response to Paleoproterozoic oxygenation." Geobiology.
Version
Final published version
Abstract
Protection from radiation damage is an important adaptation for phototrophic microbes. Living in surface, shallow water, and peritidal environments, cyanobacteria are especially exposed to long-wavelength ultraviolet (UVA) radiation. Several groups of cyanobacteria within these environments are protected from UVA damage by the production of the pigment scytonemin. Paleontological evidence of cyanobacteria in UVA-exposed environments from the Proterozoic, and possibly as early as the Archaean, suggests a long evolutionary history of radiation protection within this group. We show that phylogenetic analyses of enzymes in the scytonemin biosynthesis pathway support this hypothesis and reveal a deep history of vertical inheritance of this pathway within extant cyanobacterial diversity. Referencing this phylogeny to cyanobacterial molecular clocks suggests that scytonemin production likely appeared during the early Proterozoic, soon after the Great Oxygenation Event. This timing is consistent with an adaptive scenario for the evolution of scytonemin production, wherein the threat of UVA-generated reactive oxygen species becomes significantly greater once molecular oxygen is more pervasive across photosynthetic environments.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1111/gbi.12514
