| Autor: |
Lee A. Rettberg, Wonchull Kang, Martin T. Stiebritz, Caleb J. Hiller, Chi Chung Lee, Jasper Liedtke, Markus W. Ribbe, Yilin Hu |
| Jazyk: |
angličtina |
| Rok vydání: |
2019 |
| Předmět: |
|
| Zdroj: |
mBio, Vol 10, Iss 4 (2019) |
| Druh dokumentu: |
article |
| ISSN: |
2150-7511 |
| DOI: |
10.1128/mBio.01497-19 |
| Popis: |
ABSTRACT Nitrogenase iron (Fe) proteins reduce CO2 to CO and/or hydrocarbons under ambient conditions. Here, we report a 2.4-Å crystal structure of the Fe protein from Methanosarcina acetivorans (MaNifH), which is generated in the presence of a reductant, dithionite, and an alternative CO2 source, bicarbonate. Structural analysis of this methanogen Fe protein species suggests that CO2 is possibly captured in an unactivated, linear conformation near the [Fe4S4] cluster of MaNifH by a conserved arginine (Arg) pair in a concerted and, possibly, asymmetric manner. Density functional theory calculations and mutational analyses provide further support for the capture of CO2 on MaNifH while suggesting a possible role of Arg in the initial coordination of CO2 via hydrogen bonding and electrostatic interactions. These results provide a useful framework for further mechanistic investigations of CO2 activation by a surface-exposed [Fe4S4] cluster, which may facilitate future development of FeS catalysts for ambient conversion of CO2 into valuable chemical commodities. IMPORTANCE This work reports the crystal structure of a previously uncharacterized Fe protein from a methanogenic organism, which provides important insights into the structural properties of the less-characterized, yet highly interesting archaeal nitrogenase enzymes. Moreover, the structure-derived implications for CO2 capture by a surface-exposed [Fe4S4] cluster point to the possibility of developing novel strategies for CO2 sequestration while providing the initial insights into the unique mechanism of FeS-based CO2 activation. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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