6N2N

Crystal structure of 2-oxoglutarate:ferredoxin oxidoreductase from Magnetococcus marinus

Summary for 6N2N

• Entry DOI: 10.2210/pdb6n2n/pdb
• Related: 6N2O
• Descriptor: Pyruvate flavodoxin/ferredoxin oxidoreductase domain protein, Pyruvate ferredoxin/flavodoxin oxidoreductase, beta subunit, SULFATE ION, ... (7 entities in total)
• Functional Keywords: thiamine pyrophosphate, [4fe-4s] cluster, carbon fixation, reductive tricarboxylic acid cycle, rtca, 2-oxoglutarate:ferredoxin oxidoreductase, electron transfer, oxidoreductase
• Biological source: Magnetococcus marinus (strain ATCC BAA-1437 / JCM 17883 / MC-1); More
• Total number of polymer chains: 4
• Total formula weight: 189718.70

Authors

Chen, P.Y.-T.,Drennan, C.L. (deposition date: 2018-11-13, release date: 2019-03-20, Last modification date: 2023-10-11)

Primary citation

Chen, P.Y.,Li, B.,Drennan, C.L.,Elliott, S.J.
A reverse TCA cycle 2-oxoacid:ferredoxin oxidoreductase that makes C-C bonds from CO2.
Joule, 3:595-611, 2019

PubMed Abstract: 2-oxoglutarate:ferredoxin oxidoreductase (OGOR) is a thiamine pyrophosphate (TPP) and [4Fe-4S] cluster-dependent enzyme from the reductive tricarboxylic acid (rTCA) cycle that fixes CO to succinyl-CoA, forming 2-oxoglutarate and CoA. Here we report an OGOR from the rTCA cycle of MC-1, along with all three potential ferredoxin (Fd) redox partners. We demonstrate OGOR operates bidirectionally (both CO-fixing and 2-oxoglutarate oxidizing), and that only one Fd (Fd1) supports efficient catalysis. Our 1.94-Å and 2.80-Å resolution crystal structures of native and substrate-bound forms of OGOR reveal the determinants of substrate specificity and CoA-binding in an OGOR, and illuminate the [4Fe-4S] cluster environment, portraying the electronic conduit allowing Fd1 to be wired to the bound-TPP. Structural and biochemical data further identify Glu45α as a mobile residue that impacts catalytic bias toward CO-fixation although it makes no direct contact with TPP-bound intermediates, indicating that reaction directionality can be tuned by second layer interactions. (149 of 150 words limit).

PubMed: 31080943
DOI: 10.1016/j.joule.2018.12.006

Experimental method

X-RAY DIFFRACTION (1.937 Å)