Mg2+, K+, and the Ribosome
Mg2+ and K+ are the prevalent di- and monovalent cations inside the cells in all three domains, playing a dominant role in structure and function of biological macromolecules. Ribosomes bind a substantial fraction of total Mg2+ and K+ cations. In this issue of the Journal of Bacteriology, Akanuma and coworkers (G. Akanuma et al., J. Bacteriol. 196:3820–3830, 2014, doi:10.1128/JB.01896-14) report a surprising genetic link between ribosome amounts per cell and the intracellular Mg2+ concentrations.