Calculating metalation in cells reveals CobW acquires CoII for vitamin B12 biosynthesis while related proteins prefer ZnII

Young, Tessa R., Martini, Maria Alessandra, Foster, Andrew W., Glasfeld, Arthur, Osman, Deenah, Morton, Richard J., Deery, Evelyne, Warren, Martin J. ORCID: and Robinson, Nigel J. (2021) Calculating metalation in cells reveals CobW acquires CoII for vitamin B12 biosynthesis while related proteins prefer ZnII. Nature Communications, 12 (1). ISSN 2041-1723

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Protein metal-occupancy (metalation) in vivo has been elusive. To address this challenge, the available free energies of metals have recently been determined from the responses of metal sensors. Here, we use these free energy values to develop a metalation-calculator which accounts for inter-metal competition and changing metal-availabilities inside cells. We use the calculator to understand the function and mechanism of GTPase CobW, a predicted CoII-chaperone for vitamin B12. Upon binding nucleotide (GTP) and MgII, CobW assembles a high-affinity site that can obtain CoII or ZnII from the intracellular milieu. In idealised cells with sensors at the mid-points of their responses, competition within the cytosol enables CoII to outcompete ZnII for binding CobW. Thus, CoII is the cognate metal. However, after growth in different [CoII], CoII-occupancy ranges from 10 to 97% which matches CobW-dependent B12 synthesis. The calculator also reveals that related GTPases with comparable ZnII affinities to CobW, preferentially acquire ZnII due to their relatively weaker CoII affinities. The calculator is made available here for use with other proteins.

Item Type: Article
Additional Information: Funding Information: This work was supported by a COFUND European Union/Durham University Junior Research Fellowship under EU grant agreement 609412 (T.R.Y.), a Royal Commission for the Exhibition of 1851 Research Fellowship (T.R.Y.), an UKRI Future Leaders Fellowship MR/T019891/1 (R.J.M.), a US-UK Fulbright Commission award (A.G.), Biotechnology and Biological Sciences Research Council awards BB/S009787/1, BB/J017787/1, BB/ R002118/1, BB/S002197/1, BB/S014020/1 and Royal Society award INF\R2\180062. We thank Peter Chivers (Durham University, UK) for constructive scientific discussions. Publisher Copyright: © 2021, The Author(s).
Uncontrolled Keywords: chemistry(all),biochemistry, genetics and molecular biology(all),physics and astronomy(all) ,/dk/atira/pure/subjectarea/asjc/1600
Faculty \ School: Faculty of Science
UEA Research Groups: Faculty of Medicine and Health Sciences > Research Centres > Norwich Institute for Healthy Aging
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Depositing User: LivePure Connector
Date Deposited: 21 Sep 2022 12:31
Last Modified: 19 Apr 2023 01:13
DOI: 10.1038/s41467-021-21479-8


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