A Proterozoic microbial origin of extant cyanide-hydrolyzing enzyme diversity

Sarah L Schwartz; L Thiberio Rangel; Jack G Payette; Gregory P Fournier

doi:10.3389/fmicb.2023.1130310

A Proterozoic microbial origin of extant cyanide-hydrolyzing enzyme diversity

Front Microbiol. 2023 Mar 30:14:1130310. doi: 10.3389/fmicb.2023.1130310. eCollection 2023.

Authors

Sarah L Schwartz^{1

2

3}, L Thiberio Rangel³, Jack G Payette³, Gregory P Fournier³

Affiliations

¹ Department of Civil and Environmental Engineering, University of California, Berkeley, Berkeley, CA, United States.
² Graduate Program in Microbiology, Massachusetts Institute of Technology, Cambridge, MA, United States.
³ Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States.

Abstract

In addition to its role as a toxic environmental contaminant, cyanide has been hypothesized to play a key role in prebiotic chemistry and early biogeochemical evolution. While cyanide-hydrolyzing enzymes have been studied and engineered for bioremediation, the extant diversity of these enzymes remains underexplored. Additionally, the age and evolution of microbial cyanide metabolisms is poorly constrained. Here we provide comprehensive phylogenetic and molecular clock analyses of the distribution and evolution of the Class I nitrilases, thiocyanate hydrolases, and nitrile hydratases. Molecular clock analyses indicate that bacterial cyanide-reducing nitrilases were present by the Paleo- to Mesoproterozoic, and were subsequently horizontally transferred into eukaryotes. These results present a broad diversity of microbial enzymes that could be optimized for cyanide bioremediation.

Keywords: cyanide; molecular clock; nitrilase; nitrile; nitrile hydratase; phylogenetics; thiocyanate hydrolase.

Associated data

figshare/10.6084/m9.figshare.c.5952186