%0 Journal Article %A Huergo, Luciano F. %A Pedrosa, Fábio O. %A Muller-Santos, Marcelo %A Chubatsu, Leda S. %A Monteiro, Rose A. %A Merrick, Mike %A Souza, Emanuel M. %T PII signal transduction proteins: pivotal players in post-translational control of nitrogenase activity %D 2012 %J Microbiology, %V 158 %N 1 %P 176-190 %@ 1465-2080 %R https://doi.org/10.1099/mic.0.049783-0 %I Microbiology Society, %X The fixation of atmospheric nitrogen by the prokaryotic enzyme nitrogenase is an energy- expensive process and consequently it is tightly regulated at a variety of levels. In many diazotrophs this includes post-translational regulation of the enzyme’s activity, which has been reported in both bacteria and archaea. The best understood response is the short-term inactivation of nitrogenase in response to a transient rise in ammonium levels in the environment. A number of proteobacteria species effect this regulation through reversible ADP-ribosylation of the enzyme, but other prokaryotes have evolved different mechanisms. Here we review current knowledge of post-translational control of nitrogenase and show that, for the response to ammonium, the PII signal transduction proteins act as key players. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.049783-0