Osman, Deenah and Martini, Maria Alessandra and Foster, Andrew W. and Chen, Junjun and Scott, Andrew J. P. and Morton, Richard J. and Steed, Jonathan W. and Lurie-Luke, Elena and Huggins, Thomas G. and Lawrence, Andrew D. and Deery, Evelyne and Warren, Martin J. and Chivers, Peter T. and Robinson, Nigel J. (2019) 'Bacterial sensors define intracellular free energies for correct enzyme metalation.', Nature chemical biology., 15 (3). pp. 241-249.
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.
|Full text:||(AM) Accepted Manuscript|
Download PDF (1224Kb)
|Publisher Web site:||https://rdcu.be/biPEi|
|Date accepted:||04 December 2018|
|Date deposited:||01 February 2019|
|Date of first online publication:||28 January 2019|
|Date first made open access:||28 July 2019|
Save or Share this output
|Look up in GoogleScholar|