title: The rise of oxygen and aerobic biochemistry.
abstract: Analysis of conserved protein folding domains across extant genomes by Kim et al. in this issue of Structure provides insights into the timing of some of the earliest aerobic metabolisms to arise on Earth.
authors.affiliation: Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA. msaito@whoi.edu
authors.forename: Mak A
authors.initials: MA
authors.lastname: Saito