1. Bacterial sensors define intracellular free energies for correct enzyme metalation.
- Author
-
Osman D, Martini MA, Foster AW, Chen J, Scott AJP, Morton RJ, Steed JW, Lurie-Luke E, Huggins TG, Lawrence AD, Deery E, Warren MJ, Chivers PT, and Robinson NJ
- Subjects
- Affinity Labels metabolism, Bacteria enzymology, Bacteria metabolism, Bacterial Physiological Phenomena, Bacterial Proteins metabolism, Bacterial Proteins physiology, Metalloproteins physiology, Salmonella metabolism, Energy Transfer physiology, Metalloproteins metabolism, Metals metabolism
- Abstract
There is a challenge for metalloenzymes to acquire their correct metals because some inorganic elements form more stable complexes with proteins than do others. These preferences can be overcome provided some metals are more available than others. However, while the total amount of cellular metal can be readily measured, the available levels of each metal have been more difficult to define. Metal-sensing transcriptional regulators are tuned to the intracellular availabilities of their cognate ions. Here we have determined the standard free energy for metal complex formation to which each sensor, in a set of bacterial metal sensors, is attuned: the less competitive the metal, the less favorable the free energy and hence the greater availability to which the cognate allosteric mechanism is tuned. Comparing these free energies with values derived from the metal affinities of a metalloprotein reveals the mechanism of correct metalation exemplified here by a cobalt chelatase for vitamin B
12 .- Published
- 2019
- Full Text
- View/download PDF