A transcription factor that links domains – Microbiology Research

Archaea combine bacterial-like cellular morphology with eukaryotic-like transcription initiation machinery. Curiously, however, their genomes are depleted of transcription factors that are found in other domains of life. A study by Medina Ferrer and Nayak identifies an archaeal transcription factor in methanogenic archaea (methanogens) that functions as a one-component system, with a eukaryotic-like DNA-binding motif.

First, the authors showed that Methanosarcina acetivorans requires a varying ‘acclimation time’ to switch from growth on one substrate to another. Based on these findings, the authors designed an evolution-based forward genetic screen to identify regulatory processes that control acclimation time during a substrate switch. Follow-up studies of loci targeted in the screen led to the discovery of MA2561 as a negative regulator of methylamine growth in M. acetivorans. A mutant lacking MA2561 expression showed highly upregulated expression of methylamine-specific MT1 genes compared with the parent strain. Moreover, in vitro studies determined that MA2561 binds to methylamines and acts as an intracellular sensor.