6KV0

Ferredoxin I from C. reinhardtii, high X-ray dose

Summary for 6KV0

• Entry DOI: 10.2210/pdb6kv0/pdb
• Descriptor: Ferredoxin, chloroplastic, FE2/S2 (INORGANIC) CLUSTER, BENZAMIDINE, ... (7 entities in total)
• Functional Keywords: [2fe2s] cluster, electron transport
• Biological source: Chlamydomonas reinhardtii
• Total number of polymer chains: 2
• Total formula weight: 20798.61

Authors

Onishi, Y.,Kurisu, G.,Tanaka, H. (deposition date: 2019-09-03, release date: 2020-05-20, Last modification date: 2024-03-27)

Primary citation

Ohnishi, Y.,Muraki, N.,Kiyota, D.,Okumura, H.,Baba, S.,Kawano, Y.,Kumasaka, T.,Tanaka, H.,Kurisu, G.
X-ray dose-dependent structural changes of the [2Fe-2S] ferredoxin from Chlamydomonas reinhardtii.
J.Biochem., 167:549-555, 2020

PubMed Abstract: Plant-type ferredoxin (Fd) is an electron transfer protein in chloroplast. Redox-dependent structural change of Fd controls its association with and dissociation from Fd-dependent enzymes. Among many X-ray structures of oxidized Fd have been reported so far, very likely a given number of them was partially reduced by strong X-ray. To understand the precise structural change between reduced and oxidized Fd, it is important to know whether the crystals of oxidized Fd may or may not be reduced during the X-ray experiment. We prepared the thin plate-shaped Fd crystals from Chlamydomonas reinhardtii and monitored its absorption spectra during experiment. Absorption spectra of oxidized Fd crystals were clearly changed to that of reduced form in an X-ray dose-dependent manner. In another independent experiment, the X-ray diffraction images obtained from different parts of one single crystal were sorted and merged to form two datasets with low and high X-ray doses. An Fo-Fo map calculated from the two datasets showed that X-ray reduction causes a small displacement of the iron atoms in the [2Fe-2S] cluster. Both our spectroscopic and crystallographic studies confirm X-ray dose-dependent reduction of Fd, and suggest a structural basis for its initial reduction step especially in the core of the cluster.

PubMed: 32282907
DOI: 10.1093/jb/mvaa045

Experimental method

X-RAY DIFFRACTION (1.4 Å)