Em busca da primeira bactéria

quinta-feira, abril 01, 2021

The metabolic network of the last bacterial common ancestor

Joana C. Xavier, Rebecca E. Gerhards, Jessica L. E. Wimmer, Julia Brueckner, Fernando D. K. Tria & William F. Martin

Communications Biology volume 4, Article number: 413 (2021)

Fig. 1: Metabolic network of LBCA expanded with 9 genes to include 57 universal biomolecules.


Abstract

Bacteria are the most abundant cells on Earth. They are generally regarded as ancient, but due to striking diversity in their metabolic capacities and widespread lateral gene transfer, the physiology of the first bacteria is unknown. From 1089 reference genomes of bacterial anaerobes, we identified 146 protein families that trace to the last bacterial common ancestor, LBCA, and form the conserved predicted core of its metabolic network, which requires only nine genes to encompass all universal metabolites. Our results indicate that LBCA performed gluconeogenesis towards cell wall synthesis, and had numerous RNA modifications and multifunctional enzymes that permitted life with low gene content. In accordance with recent findings for LUCA and LACA, analyses of thousands of individual gene trees indicate that LBCA was rod-shaped and the first lineage to diverge from the ancestral bacterial stem was most similar to modern Clostridia, followed by other autotrophs that harbor the acetyl-CoA pathway.