Exploring the (Almost) Unknown: Archaeal Two-Component Systems.

Two-component systems (TCS) exist in bacteria and archaea. In contrast to the knowledge of bacterial TCSs, little information is available on their archaeal counterparts. In the current issue of Journal of Bacteriology , Galperin and coworkers present a bioinformatics analysis of TCS genes from archaeal genome sequences (M. Y. Galperin, K. S. Makarova, Y. I. Wolf, and E. V. Koonin, J Bacteriol 200:e00681-17, 2018, https://doi.org/10.1128/JB.00681-17). This study identifies different aspects in which TCS-mediated signaling differs in bacteria and archaea and forms a sound basis for the experimental design of studies to increase our knowledge of this poorly investigated protein family.