Chongdar, Nipa and Rodríguez-Maciá, Patricia and Reijerse, Edward J and Lubitz, Wolfgang and Ogata, Hideaki and Birrell, James A (2023) Redox tuning of the H-cluster by second coordination sphere amino acids in the sensory [FeFe] hydrogenase from Thermotoga maritima. Chemical Science, 14 (13). pp. 3682-3692. DOI https://doi.org/10.1039/d2sc06432d
Chongdar, Nipa and Rodríguez-Maciá, Patricia and Reijerse, Edward J and Lubitz, Wolfgang and Ogata, Hideaki and Birrell, James A (2023) Redox tuning of the H-cluster by second coordination sphere amino acids in the sensory [FeFe] hydrogenase from Thermotoga maritima. Chemical Science, 14 (13). pp. 3682-3692. DOI https://doi.org/10.1039/d2sc06432d
Chongdar, Nipa and Rodríguez-Maciá, Patricia and Reijerse, Edward J and Lubitz, Wolfgang and Ogata, Hideaki and Birrell, James A (2023) Redox tuning of the H-cluster by second coordination sphere amino acids in the sensory [FeFe] hydrogenase from Thermotoga maritima. Chemical Science, 14 (13). pp. 3682-3692. DOI https://doi.org/10.1039/d2sc06432d
Abstract
[FeFe] hydrogenases are exceptionally active catalysts for the interconversion of molecular hydrogen with protons and electrons. Their active site, the H-cluster, is composed of a [4Fe-4S] cluster covalently linked to a unique [2Fe] subcluster. These enzymes have been extensively studied to understand how the protein environment tunes the properties of the Fe ions for efficient catalysis. The sensory [FeFe] hydrogenase (HydS) from <i>Thermotoga maritima</i> has low activity and displays a very positive redox potential for the [2Fe] subcluster compared to that of the highly active prototypical enzymes. Using site directed mutagenesis, we investigate how second coordination sphere interactions of the protein environment with the H-cluster in HydS influence the catalytic, spectroscopic and redox properties of the H-cluster. In particular, mutation of the non-conserved serine 267, situated between the [4Fe-4S] and [2Fe] subclusters, to methionine (conserved in prototypical catalytic enzymes) gave a dramatic decrease in activity. Infra-red (IR) spectroelectrochemistry revealed a 50 mV lower redox potential for the [4Fe-4S] subcluster in the S267M variant. We speculate that this serine forms a hydrogen bond to the [4Fe-4S] subcluster, increasing its redox potential. These results demonstrate the importance of the secondary coordination sphere in tuning the catalytic properties of the H-cluster in [FeFe] hydrogenases and reveal a particularly important role for amino acids interacting with the [4Fe-4S] subcluster.
Item Type: | Article |
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Divisions: | Faculty of Science and Health Faculty of Science and Health > Life Sciences, School of |
SWORD Depositor: | Unnamed user with email elements@essex.ac.uk |
Depositing User: | Unnamed user with email elements@essex.ac.uk |
Date Deposited: | 17 Apr 2023 12:26 |
Last Modified: | 07 Aug 2024 20:17 |
URI: | http://repository.essex.ac.uk/id/eprint/35402 |
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