| Autor: |
Harshwardhan Poddar, Ronald Rios-Santacruz, Derren J. Heyes, Muralidharan Shanmugam, Adam Brookfield, Linus O. Johannissen, Colin W. Levy, Laura N. Jeffreys, Shaowei Zhang, Michiyo Sakuma, Jacques-Philippe Colletier, Sam Hay, Giorgio Schirò, Martin Weik, Nigel S. Scrutton, David Leys |
| Jazyk: |
angličtina |
| Rok vydání: |
2023 |
| Předmět: |
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| Zdroj: |
Nature Communications, Vol 14, Iss 1, Pp 1-14 (2023) |
| Druh dokumentu: |
article |
| ISSN: |
2041-1723 |
| DOI: |
10.1038/s41467-023-40817-6 |
| Popis: |
Abstract CarH is a coenzyme B12-dependent photoreceptor involved in regulating carotenoid biosynthesis. How light-triggered cleavage of the B12 Co-C bond culminates in CarH tetramer dissociation to initiate transcription remains unclear. Here, a series of crystal structures of the CarH B12-binding domain after illumination suggest formation of unforeseen intermediate states prior to tetramer dissociation. Unexpectedly, in the absence of oxygen, Co-C bond cleavage is followed by reorientation of the corrin ring and a switch from a lower to upper histidine-Co ligation, corresponding to a pentacoordinate state. Under aerobic conditions, rapid flash-cooling of crystals prior to deterioration upon illumination confirm a similar B12-ligand switch occurs. Removal of the upper His-ligating residue prevents monomer formation upon illumination. Combined with detailed solution spectroscopy and computational studies, these data demonstrate the CarH photoresponse integrates B12 photo- and redox-chemistry to drive large-scale conformational changes through stepwise Co-ligation changes. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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