8C35

Dark state 2.1 Angstrom crystal structure of H132A variant of cobalamin binding domain belonging to a light-dependent transcription regulator TtCarH

8C35 の概要

• エントリーDOI: 10.2210/pdb8c35/pdb
• 分子名称: Probable transcriptional regulator, COBALAMIN, 5'-DEOXYADENOSINE, ... (4 entities in total)
• 機能のキーワード: carh, cobalamin, light-activated, transcription regulator, transcription
• 由来する生物種: Thermus thermophilus HB27
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 99097.31

構造登録者

Poddar, H.,Leys, D. (登録日: 2022-12-23, 公開日: 2023-08-16, 最終更新日: 2023-08-30)

主引用文献

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

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: 37604813
DOI: 10.1038/s41467-023-40817-6

実験手法

X-RAY DIFFRACTION (2.1 Å)