8C73
Dark state 1.8 Angstrom crystal structure of cobalamin binding domain belonging to a light-dependent transcription regulator TtCarH obtained under aerobic condition form ll
Summary for 8C73
Entry DOI | 10.2210/pdb8c73/pdb |
Descriptor | Probable transcriptional regulator, 5'-DEOXYADENOSINE, COBALAMIN, ... (4 entities in total) |
Functional Keywords | b12, adocobalamin, adenosylcobalamine, photoreceptor, light-sensitive protein, dna binding protein |
Biological source | Thermus thermophilus |
Total number of polymer chains | 4 |
Total formula weight | 99365.60 |
Authors | Rios-Santacruz, R.,Colletier, J.P.,Schiro, G.,Weik, M. (deposition date: 2023-01-12, release date: 2023-08-09, Last modification date: 2023-08-30) |
Primary citation | Poddar, H.,Rios-Santacruz, R.,Heyes, D.J.,Shanmugam, M.,Brookfield, A.,Johannissen, L.O.,Levy, C.W.,Jeffreys, L.N.,Zhang, S.,Sakuma, M.,Colletier, J.P.,Hay, S.,Schiro, G.,Weik, M.,Scrutton, N.S.,Leys, D. Redox driven B 12 -ligand switch drives CarH photoresponse. Nat Commun, 14:5082-5082, 2023 Cited by PubMed Abstract: CarH is a coenzyme B-dependent photoreceptor involved in regulating carotenoid biosynthesis. How light-triggered cleavage of the B Co-C bond culminates in CarH tetramer dissociation to initiate transcription remains unclear. Here, a series of crystal structures of the CarH B-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 B-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 B photo- and redox-chemistry to drive large-scale conformational changes through stepwise Co-ligation changes. PubMed: 37604813DOI: 10.1038/s41467-023-40817-6 PDB entries with the same primary citation |
Experimental method | X-RAY DIFFRACTION (1.7 Å) |
Structure validation
Download full validation report