ANCIENT METABOLISMS

About 2.5 billion years ago there was a massive increase in oxygen in the Earth’s atmosphere and we infer that these changes were, in part, being driven or governed by protein behavior. We focus on proteins that are thought to be essential for early metabolisms and study how they may have changed themselves and how in turn this could have changed our environment.We rely on phylogenetic tree reconstructions to infer the evolutionary history of genes and proteins. We reconstruct selected gene sequences from the built trees and characterize the properties of these synthetized ancient proteins in the laboratory either biochemically or by engineering them inside bacterial genomes. In order to understand how the ancestral behavior of proteins and their host systems change through time, we are reconstructing key proteins that are involved in phenotypically distinct metabolic pathways that are of interest to biologists and geologists. Through our collaborations with paleobiologists and phylogeneticists, we aim to answer the question of whether the phenotypes we observe relate to larger scale changes in the global biogeochemical system.

 

 

Current Projects

Ancient biochemical evolution of nitrogenase through the history of Earth oxygenation

 

Molecular Evolution of Rubisco proteins

 

Biochemical, Genetic, Metabolic and Isotopic Constraints on an Ancient Thiobiosphere

Key Papers

 

Constraining the timing of the Great Oxidation Event within the Rubisco phylogenetic tree. Read Paper >>>

Resurrecting ancestral genes in bacteria to interpret ancient biosignatures. Read Paper >>>

 

The origin of animals as microbial host volumes in nutrient-limited seas. Read Paper >>>

Recent Highlights

 

Read Betul’s interview with PLoS Blogs

NASA highlights our work on Rubisco proteins

New Scientist article discussing how resurrected genes may allow time travel to an Earth before oxygen

 

Key Collaborators

 

NSF Ideas Lab Protobiology Group ​

© 2019 Kacar Research Group

University of Arizona, 1007 E Lowell St, Tucson, AZ 85719

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