Bacterial sensors define intracellular free energies for correct enzyme metalation

Deenah Osman, Maria Alessandra Martini, Andrew W. Foster, Junjun Chen, Andrew J. P. Scott, Richard J. Morton, Jonathan W. Steed, Elena Lurie-Luke, Thomas G. Huggins, Andrew D. Lawrence, Evelyne Deery, Martin J. Warren, Peter T. Chivers, Nigel J. Robinson

Research output: Contribution to journalArticlepeer-review

92 Citations (Scopus)


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 B12.
Original languageEnglish
Pages (from-to)241-249
Number of pages9
JournalNature Chemical Biology
Issue number3
Early online date28 Jan 2019
Publication statusPublished - 1 Mar 2019

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