TY - GEN A1 - Commichau, Fabian M. A1 - Gibhardt, Johannes A1 - Heidemann, Jana A1 - Bremenkamp, Rica A1 - Rosenberg, Jonathan A1 - Seifert, Roland A1 - Kaever, Volkhard A1 - Ficner, Ralf T1 - An extracytoplasmic protein and a moonlighting enzyme modulate synthesis of c-di-AMP in Listeria monocytogenes T2 - Environmental Microbiology N2 - The second messenger cyclic di-AMP (c-di-AMP) is essential for growth of many bacteria because it controls osmolyte homeostasis. c-di-AMP can regulate the synthesis of potassium uptake systems in some bacteria and it also directly inhibits and activates potassium import and export systems, respectively. Therefore, c-di-AMP production and degradation have to be tightly regulated depending on the environmental osmolarity. The Gram-positive pathogen Listeria monocytogenes relies on the membrane-bound diadenylate cyclase CdaA for c-di-AMP production and degrades the nucleotide with two phosphodiesterases. While the enzymes producing and degrading the dinucleotide have been reasonably well examined, the regulation of c-di-AMP production is not well understood yet. Here we demonstrate that the extracytoplasmic regulator CdaR interacts with CdaA via its transmembrane helix to modulate c-di-AMP production. Moreover, we show that the phosphoglucosamine mutase GlmM forms a complex with CdaA and inhibits the diadenylate cyclase activity in vitro. We also found that GlmM inhibits c-di-AMP production in L. monocytogenes when the bacteria encounter osmotic stress. Thus, GlmM is the major factor controlling the activity of CdaA in vivo. GlmM can be assigned to the class of moonlighting proteins because it is active in metabolism and adjusts the cellular turgor depending on environmental osmolarity. Y1 - 2020 UR - https://sfamjournals.onlinelibrary.wiley.com/doi/full/10.1111/1462-2920.15008 U6 - https://doi.org/10.1111/1462-2920.15008 SN - 1462-2920 SN - 1462-2912 VL - 22 IS - 7 SP - 2771 EP - 2791 ER -