1
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Britt RD, Rauchfuss TB, Rao G. The H-cluster of [FeFe] Hydrogenases: Its Enzymatic Synthesis and Parallel Inorganic Semisynthesis. Acc Chem Res 2024; 57:1941-1950. [PMID: 38937148 PMCID: PMC11256358 DOI: 10.1021/acs.accounts.4c00231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 06/12/2024] [Accepted: 06/14/2024] [Indexed: 06/29/2024]
Abstract
ConspectusNature's prototypical hydrogen-forming catalysts─hydrogenases─have attracted much attention because they catalyze hydrogen evolution at near zero overpotential and ambient conditions. Beyond any possible applications in the energy sphere, the hydrogenases feature complicated active sites, which implies novel biosynthetic pathways. In terms of the variety of cofactors, the [FeFe]-hydrogenase is among the most complex.For more than a decade, we have worked on the biosynthesis of the active site of [FeFe] hydrogenases. This site, the H-cluster, is a six-iron ensemble consisting of a [4Fe-4S]H cluster linked to a [2Fe]H cluster that is coordinated to CO, cyanide, and a unique organic azadithiolate ligand. Many years ago, three enzymes, namely, HydG, HydE, and HydF, were shown to be required for the biosynthesis and the in vitro maturation of [FeFe] hydrogenases. The structures of the maturases were determined crystallographically, but still little progress was made on the biosynthetic pathway. As described in this Account, the elucidation of the biosynthetic pathway began in earnest with the identification of a molecular iron-cysteinate complex produced within HydG.In this Account, we present our most recent progress toward the molecular mechanism of [2Fe]H biosynthesis using a collaborative approach involving cell-free biosynthesis, isotope and element-sensitive spectroscopies, as well as inorganic synthesis of purported biosynthetic intermediates. Our study starts from the radical SAM enzyme HydG that lyses tyrosine into CO and cyanide and forms an Fe(CO)2(CN)-containing species. Crystallographic identification of a unique auxiliary 5Fe-4S cluster in HydG leads to a proposed catalytic cycle in which a free cysteine-chelated "dangler" Fe serves as the platform for the stepwise formation of a [4Fe-4S][Fe(CO)(CN)(cysteinate)] intermediate, which releases the [Fe(CO)2(CN)(cysteinate)] product, Complex B. Since Complex B is unstable, we applied synthetic organometallic chemistry to make an analogue, syn-B, and showed that it fully replaces HydG in the in vitro maturation of the H-cluster. Syn-B serves as the substrate for the next radical SAM enzyme HydE, where the low-spin Fe(II) center is activated by 5'-dAdo• to form an adenosylated Fe(I) intermediate. We propose that this Fe(I) species strips the carbon backbone and dimerizes in HydE to form a [Fe2(SH)2(CO)4(CN)2]2- product. This mechanistic scenario is supported by the use of a synthetic version of this dimer complex, syn-dimer, which allows for the formation of active hydrogenase with only the HydF maturase. Further application of this semisynthesis strategy shows that an [Fe2(SCH2NH2)2(CO)4(CN)2]2- complex can activate the apo hydrogenase, marking it as the last biosynthetic intermediate en route to the H-cluster. This combined enzymatic and semisynthetic approach greatly accelerates our understanding of H-cluster biosynthesis. We anticipate additional mechanistic details regarding H-cluster biosynthesis to be gleaned, and this methodology may be further applied in the study of other complex metallocofactors.
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Affiliation(s)
- R. David Britt
- Department
of Chemistry, University of California,
Davis, Davis, California 95616, United
States
| | - Thomas B. Rauchfuss
- Department
of Chemistry, University of Illinois at
Urbana−Champaign, Urbana, Illinois 61820, United States
| | - Guodong Rao
- Department
of Chemistry, University of California,
Davis, Davis, California 95616, United
States
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2
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Haas R, Lampret O, Yadav S, Apfel UP, Happe T. A Conserved Binding Pocket in HydF is Essential for Biological Assembly and Coordination of the Diiron Site of [FeFe]-Hydrogenases. J Am Chem Soc 2024; 146:15771-15778. [PMID: 38819401 DOI: 10.1021/jacs.4c01635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2024]
Abstract
The active site cofactor of [FeFe]-hydrogenases consists of a cubane [4Fe-4S]-cluster and a unique [2Fe-2S]-cluster, harboring unusual CO- and CN--ligands. The biosynthesis of the [2Fe-2S]-cluster requires three dedicated maturation enzymes called HydG, HydE and HydF. HydG and HydE are both involved in synthesizing a [2Fe-2S]-precursor, still lacking parts of the azadithiolate (adt) moiety that bridge the two iron atoms. This [2Fe-2S]-precursor is then finalized within the scaffold protein HydF, which binds and transfers the [2Fe-2S]-precursor to the hydrogenase. However, its exact binding mode within HydF is still elusive. Herein, we identified the binding location of the [2Fe-2S]-precursor by altering size and charge of a highly conserved protein pocket via site directed mutagenesis (SDM). Moreover, we identified two serine residues that are essential for binding and assembling the [2Fe-2S]-precursor. By combining SDM and molecular docking simulations, we provide a new model on how the [2Fe-2S]-cluster is bound to HydF and demonstrate the important role of one highly conserved aspartate residue, presumably during the bioassembly of the adt moiety.
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Affiliation(s)
- Rieke Haas
- Photobiotechnology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801 Bochum, Germany
| | - Oliver Lampret
- Photobiotechnology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801 Bochum, Germany
| | - Shanika Yadav
- Inorganic Chemistry I, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44801 Bochum, Germany
| | - Ulf-Peter Apfel
- Inorganic Chemistry I, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44801 Bochum, Germany
| | - Thomas Happe
- Photobiotechnology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801 Bochum, Germany
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3
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Yu X, Rao G, Britt RD, Rauchfuss TB. Final Stages in the Biosynthesis of the [FeFe]-Hydrogenase Active Site. Angew Chem Int Ed Engl 2024; 63:e202404044. [PMID: 38551577 PMCID: PMC11253240 DOI: 10.1002/anie.202404044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Indexed: 04/19/2024]
Abstract
The paper aims to elucidate the final stages in the biosynthesis of the [2Fe]H active site of the [FeFe]-hydrogenases. The recently hypothesized intermediate [Fe2(SCH2NH2)2(CN)2(CO)4]2- ([1]2-) was prepared by a multistep route from [Fe2(S2)(CN)(CO)5]-. The following synthetic intermediates were characterized in order: [Fe2(SCH2NHFmoc)2(CNBEt3)(CO)5]-, [Fe2(SCH2NHFmoc)2(CN)-(CO)5]-, and [Fe2(SCH2NHFmoc)2(CN)2(CO)4]2-, where Fmoc is fluorenylmethoxycarbonyl). Derivatives of these anions include [K(18-crown-6)]+, PPh4 + and PPN+ salts as well as the 13CD2-isotopologues. These Fe2 species exist as a mixture of two isomers attributed to diequatorial (ee) and axial-equatorial (ae) stereochemistry at sulfur. In vitro experiments demonstrate that [1]2- maturates HydA1 in the presence of HydF and a cocktail of reagents. HydA1 can also be maturated using a highly simplified cocktail, omitting HydF and other proteins. This result is consistent with HydA1 participating in the maturation process and refines the roles of HydF.
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Affiliation(s)
- Xin Yu
- School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Guodong Rao
- Department of Chemistry, University of California, Davis, CA 95616, USA
| | - R. David Britt
- Department of Chemistry, University of California, Davis, CA 95616, USA
| | - Thomas B. Rauchfuss
- School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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4
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Omeiri J, Martin L, Usclat A, Cherrier MV, Nicolet Y. Maturation of the [FeFe]-Hydrogenase: Direct Transfer of the (κ 3 -cysteinate)Fe II (CN)(CO) 2 Complex B from HydG to HydE. Angew Chem Int Ed Engl 2023; 62:e202314819. [PMID: 37962296 DOI: 10.1002/anie.202314819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 11/13/2023] [Accepted: 11/14/2023] [Indexed: 11/15/2023]
Abstract
[FeFe]-hydrogenases efficiently catalyze the reversible oxidation of molecular hydrogen. Their prowess stems from the intricate H-cluster, combining a [Fe4 S4 ] center with a binuclear iron center ([2Fe]H ). In the latter, each iron atom is coordinated by a CO and CN ligand, connected by a CO and an azadithiolate ligand. The synthesis of this active site involves a unique multiprotein assembly, featuring radical SAM proteins HydG and HydE. HydG initiates the transformation of L-tyrosine into cyanide and carbon monoxide to generate complex B, which is subsequently transferred to HydE to continue the biosynthesis of the [2Fe]H -subcluster. Due to its instability, complex B isolation for structural or spectroscopic characterization has been elusive thus far. Nevertheless, the use of a biomimetic analogue of complex B allowed circumvention of the need for the HydG protein during in vitro functional investigations, implying a similar structure for complex B. Herein, we used the HydE protein as a nanocage to encapsulate and stabilize the complex B product generated by HydG. Using X-ray crystallography, we successfully determined its structure at 1.3 Å resolution. Furthermore, we demonstrated that complex B is directly transferred from HydG to HydE, thus not being released into the solution post-synthesis, highlighting a transient interaction between the two proteins.
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Affiliation(s)
- Juneina Omeiri
- Univ. Grenoble-Alpes, CEA, CNRS, IBS, Metalloproteins Unit, 38000, Grenoble, France
| | - Lydie Martin
- Univ. Grenoble-Alpes, CEA, CNRS, IBS, Metalloproteins Unit, 38000, Grenoble, France
| | - Anthony Usclat
- Univ. Grenoble-Alpes, CEA, CNRS, IBS, Metalloproteins Unit, 38000, Grenoble, France
| | - Mickael V Cherrier
- Univ. Grenoble-Alpes, CEA, CNRS, IBS, Metalloproteins Unit, 38000, Grenoble, France
| | - Yvain Nicolet
- Univ. Grenoble-Alpes, CEA, CNRS, IBS, Metalloproteins Unit, 38000, Grenoble, France
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Villarreal DG, Rao G, Tao L, Liu L, Rauchfuss TB, Britt RD. Characterizing the Biosynthesis of the [Fe(II)(CN)(CO) 2(cysteinate)] - Organometallic Product of the Radical-SAM Enzyme HydG by EPR and Mössbauer Spectroscopy. J Phys Chem B 2023; 127:9295-9302. [PMID: 37861415 DOI: 10.1021/acs.jpcb.3c05495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2023]
Abstract
[FeFe]-hydrogenases employ a catalytic H-cluster, consisting of a [4Fe-4S]H cluster linked to a [2Fe]H subcluster with CO, CN- ligands, and an azadithiolate bridge, which mediates the rapid redox interconversion of H+ and H2. In the biosynthesis of this H-cluster active site, the radical S-adenosyl-l-methionine (radical SAM, RS) enzyme HydG plays the crucial role of generating an organometallic [Fe(II)(CN)(CO)2(cysteinate)]- product that is en route to forming the H-cluster. Here, we report direct observation of this diamagnetic organometallic Fe(II) complex through Mössbauer spectroscopy, revealing an isomer shift of δ = 0.10 mm s-1 and quadrupole splitting of ΔEQ = 0.66 mm s-1. These Mössbauer values are a change from the starting values of δ = 1.15 mm s-1 and ΔEQ = 3.23 mm s-1 for the ferrous "dangler" Fe in HydG. These values of the observed product complex B are in good agreement with Mössbauer parameters for the low-spin Fe2+ ions in synthetic analogues, such as 57Fe Syn-B, which we report here. These results highlight the essential role that HydG plays in converting a resting-state high-spin Fe(II) to a low-spin organometallic Fe(II) product that can be transferred to the downstream maturase enzymes.
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Affiliation(s)
- David G Villarreal
- Department of Chemistry, University of California Davis, Davis, California 95616, United States
| | - Guodong Rao
- Department of Chemistry, University of California Davis, Davis, California 95616, United States
| | - Lizhi Tao
- Department of Chemistry, University of California Davis, Davis, California 95616, United States
| | - Liang Liu
- School of Chemical Sciences, University of Illinois at Urbana─Champaign, Urbana, Illinois 61801, United States
| | - Thomas B Rauchfuss
- School of Chemical Sciences, University of Illinois at Urbana─Champaign, Urbana, Illinois 61801, United States
| | - R David Britt
- Department of Chemistry, University of California Davis, Davis, California 95616, United States
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6
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Rao G, Yu X, Zhang Y, Rauchfuss TB, Britt RD. Fully Refined Semisynthesis of the [FeFe] Hydrogenase H-Cluster. Biochemistry 2023; 62:2868-2877. [PMID: 37691492 DOI: 10.1021/acs.biochem.3c00393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
[FeFe] hydrogenases contain a 6-Fe cofactor that serves as the active site for efficient redox interconversion between H2 and protons. The biosynthesis of the so-called H-cluster involves unusual enzymatic reactions that synthesize organometallic Fe complexes containing azadithiolate, CO, and CN- ligands. We have previously demonstrated that specific synthetic [Fe(CO)x(CN)y] complexes can be used to functionally replace proposed Fe intermediates in the maturation reaction. Here, we report the results from performing such cluster semisynthesis in the context of a recent fully defined cluster maturation procedure, which eliminates unknown components previously employed from Escherichia coli cell lysate and demonstrate this provides a concise route to H-cluster synthesis. We show that formaldehyde can be used as a simple reagent as the carbon source of the bridging adt ligand of H-cluster in lieu of serine/serine hydroxymethyltransferase. In addition to the actual H-cluster, we observe the formation of several H-cluster-like species, the identities of which are probed by cryogenic photolysis combined with EPR/ENDOR spectroscopy.
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Affiliation(s)
- Guodong Rao
- Department of Chemistry, University of California, Davis, Davis, California 95616, United States
| | - Xin Yu
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61820, United States
| | - Yu Zhang
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61820, United States
| | - Thomas B Rauchfuss
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61820, United States
| | - R David Britt
- Department of Chemistry, University of California, Davis, Davis, California 95616, United States
- Miller Institute for Basic Research in Science, University of California, Berkeley, Berkeley, California 94720, United States
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7
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Balci B, O'Neill RD, Shepard EM, Pagnier A, Marlott A, Mock MT, Broderick WE, Broderick JB. Semisynthetic maturation of [FeFe]-hydrogenase using [Fe 2(μ-SH) 2(CN) 2(CO) 4] 2-: key roles for HydF and GTP. Chem Commun (Camb) 2023. [PMID: 37376915 DOI: 10.1039/d3cc02169f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
Here we describe maturation of the [FeFe]-hydrogenase from its [4Fe-4S]-bound precursor state by using the synthetic complex [Fe2(μ-SH)2(CN)2(CO)4]2- together with HydF and components of the glycine cleavage system, but in the absence of the maturases HydE and HydG. This semisynthetic and fully-defined maturation provides new insights into the nature of H-cluster biosynthesis.
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Affiliation(s)
- Batuhan Balci
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, MT 59717, USA.
| | - Roark D O'Neill
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, MT 59717, USA.
| | - Eric M Shepard
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, MT 59717, USA.
| | - Adrien Pagnier
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, MT 59717, USA.
| | - Alexander Marlott
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, MT 59717, USA.
| | - Michael T Mock
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, MT 59717, USA.
| | - William E Broderick
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, MT 59717, USA.
| | - Joan B Broderick
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, MT 59717, USA.
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8
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Wang N, Zhang XP, Han J, Lei H, Zhang Q, Zhang H, Zhang W, Apfel UP, Cao R. Promoting hydrogen evolution reaction with a sulfonic proton relay. CHINESE JOURNAL OF CATALYSIS 2023. [DOI: 10.1016/s1872-2067(22)64183-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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9
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Pagnier A, Balci B, Shepard EM, Yang H, Warui DM, Impano S, Booker SJ, Hoffman BM, Broderick WE, Broderick JB. [FeFe]-Hydrogenase: Defined Lysate-Free Maturation Reveals a Key Role for Lipoyl-H-Protein in DTMA Ligand Biosynthesis. Angew Chem Int Ed Engl 2022; 61:e202203413. [PMID: 35319808 PMCID: PMC9117470 DOI: 10.1002/anie.202203413] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Indexed: 11/09/2022]
Abstract
Maturation of [FeFe]-hydrogenase (HydA) involves synthesis of a CO, CN- , and dithiomethylamine (DTMA)-coordinated 2Fe subcluster that is inserted into HydA to make the active hydrogenase. This process requires three maturation enzymes: the radical S-adenosyl-l-methionine (SAM) enzymes HydE and HydG, and the GTPase HydF. In vitro maturation with purified maturation enzymes has been possible only when clarified cell lysate was added, with the lysate presumably providing essential components for DTMA synthesis and delivery. Here we report maturation of [FeFe]-hydrogenase using a fully defined system that includes components of the glycine cleavage system (GCS), but no cell lysate. Our results reveal for the first time an essential role for the aminomethyl-lipoyl-H-protein of the GCS in hydrogenase maturation and the synthesis of the DTMA ligand of the H-cluster. In addition, we show that ammonia is the source of the bridgehead nitrogen of DTMA.
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Affiliation(s)
- Adrien Pagnier
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Batuhan Balci
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Eric M Shepard
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Hao Yang
- Department of Chemistry, Northwestern University, Evanston, IL 60208, USA
| | - Douglas M Warui
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
| | - Stella Impano
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Squire J Booker
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Brian M Hoffman
- Department of Chemistry, Northwestern University, Evanston, IL 60208, USA
| | - William E Broderick
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Joan B Broderick
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, MT 59717, USA
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10
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Zhang Y, Woods T, Rauchfuss TB. Synthesis and Dynamics of Ferrous Polychalcogenides [Fe(E x)(CN) 2(CO) 2] 2- (E = S, Se, or Te). Inorg Chem 2022; 61:8241-8249. [PMID: 35561009 PMCID: PMC9202235 DOI: 10.1021/acs.inorgchem.2c00684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Elemental chalcogens react with [Fe(CN)2(CO)3]2- to give the following ferrous derivatives: [K(18-crown-6)]2[Fe(S5)(CN)2(CO)2], [K(18-crown-6)]2[Fe(S2)(CN)2(CO)2], [K(18-crown-6)]2[Fe(Se4)(CN)2(CO)2], [K(18-crown-6)]2[Fe(Te2)(CN)2(CO)2], and (NEt4)2[Fe(Te2)(CN)2(CO)2]. While these complex anions crystallized in a single stereochemistry (i.e., trans dicyanides or cis dicyanides), they isomerize in solution upon irradiation. The results are benchmarked by the corresponding studies on benzyl thiolate [K(18-crown-6)]2[Fe(SBn)2(CN)2(CO)2].
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Affiliation(s)
- Yu Zhang
- School of Chemical Sciences, University of Illinois, Urbana, Illinois 61801, United States
| | - Toby Woods
- School of Chemical Sciences, University of Illinois, Urbana, Illinois 61801, United States
| | - Thomas B Rauchfuss
- School of Chemical Sciences, University of Illinois, Urbana, Illinois 61801, United States
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11
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Jeyachandran VR, Boal AK. Structural insights into auxiliary cofactor usage by radical S-adenosylmethionine enzymes. Curr Opin Chem Biol 2022; 68:102153. [PMID: 35512465 DOI: 10.1016/j.cbpa.2022.102153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 03/22/2022] [Accepted: 03/28/2022] [Indexed: 11/03/2022]
Abstract
Radical S-adenosylmethionine (SAM) enzymes use a common catalytic core for diverse transformations. While all radical SAM enzymes bind a Fe4S4 cluster via a characteristic tri-cysteine motif, many bind additional metal cofactors. Recently reported structures of radical SAM enzymes that use methylcobalamin or additional iron-sulfur clusters as cosubstrates show that these auxiliary units are anchored by N- and C-terminal domains that vary significantly in size and topology. Despite this architectural diversity, all use a common surface for auxiliary cofactor docking. In the sulfur insertion and metallocofactor assembly systems evaluated here, interaction with iron-sulfur cluster assembly proteins or downstream scaffold proteins is an important component of catalysis. Structures of these complexes represent important new frontiers in structural analysis of radical SAM enzymes.
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Affiliation(s)
- Vivian Robert Jeyachandran
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Amie K Boal
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA; Department of Chemistry, The Pennsylvania State University, University Park, PA, 16802, USA.
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12
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Giri DD, Dwivedi H, Khalaf D Alsukaibi A, Pal DB, Otaibi AA, Areeshi MY, Haque S, Gupta VK. Sustainable production of algae-bacteria granular consortia based biological hydrogen: New insights. BIORESOURCE TECHNOLOGY 2022; 352:127036. [PMID: 35331885 DOI: 10.1016/j.biortech.2022.127036] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 03/15/2022] [Accepted: 03/17/2022] [Indexed: 06/14/2023]
Abstract
Microbes recycling nutrient and detoxifying ecosystems are capable to fulfil the future energy need by producing biohydrogen by due to the coupling of autotrophic and heterotrophic microbes. In granules microbes mutualy exchanging nutrients and electrons for hydrogen production. The consortial biohydrogen production depend upon constituent microbes, their interdependence, competition for resources, and other operating parameters while remediating a waste material in nature or bioreactor. The present review deals with development of granular algae-bacteria consortia, hydrogen yield in coculture, important enzymes and possible engineering for improved hydrogen production.
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Affiliation(s)
- Deen Dayal Giri
- Department of Botany, Maharaj Singh College, Saharanpur-247001,Uttar Pradesh, India
| | - Himanshu Dwivedi
- Department of Botany, Maharaj Singh College, Saharanpur-247001,Uttar Pradesh, India
| | | | - Dan Bahadur Pal
- Department of Chemical Engineering, Birla Institute of Technology, Mesra, Ranchi-835215, Jharkhand, India
| | - Ahmed Al Otaibi
- Department of Chemistry, College of Sciences, University of Ha'il, Ha'il 2440, Saudi Arabia
| | - Mohammed Y Areeshi
- Research and Scientific Studies Unit, College of Nursing, Jazan University, Jazan 45142, Saudi Arabia; Medical Laboratory Technology Department, College of Applied Medical Sciences, Jazan University, Jazan 45142, Saudi Arabia
| | - Shafiul Haque
- Research and Scientific Studies Unit, College of Nursing, Jazan University, Jazan 45142, Saudi Arabia; Bursa Uludağ University Faculty of Medicine,Görükle Campus, 16059, Nilüfer, Bursa, Turkey
| | - Vijai Kumar Gupta
- Center for Safe and Improved Food, SRUC, Kings Buildings, West Mains Road, Edinburgh, EH9 3JG, UK; Biorefining and Advanced Materials Research Center, SRUC, Kings Buildings, West Mains Road, Edinburgh, EH9 3JG, UK.
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13
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L-tyrosine-bound ThiH structure reveals C-C bond break differences within radical SAM aromatic amino acid lyases. Nat Commun 2022; 13:2284. [PMID: 35477710 PMCID: PMC9046217 DOI: 10.1038/s41467-022-29980-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 04/05/2022] [Indexed: 11/08/2022] Open
Abstract
2-iminoacetate synthase ThiH is a radical S-adenosyl-L-methionine (SAM) L-tyrosine lyase and catalyzes the L-tyrosine Cα-Cβ bond break to produce dehydroglycine and p-cresol while the radical SAM L-tryptophan lyase NosL cleaves the L-tryptophan Cα-C bond to produce 3-methylindole-2-carboxylic acid. It has been difficult to understand the features that condition one C-C bond break over the other one because the two enzymes display significant primary structure similarities and presumably similar substrate-binding modes. Here, we report the crystal structure of L-tyrosine bound ThiH from Thermosinus carboxydivorans revealing an unusual protonation state of L-tyrosine upon binding. Structural comparison of ThiH with NosL and computational studies of the respective reactions they catalyze show that substrate activation is eased by tunneling effect and that subtle structural changes between the two enzymes affect, in particular, the hydrogen-atom abstraction by the 5´-deoxyadenosyl radical species, driving the difference in reaction specificity.
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14
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Pagnier A, Balci B, Shepard EM, Yang H, Warui DM, Impano S, Booker SJ, Hoffman BM, Broderick WE, Broderick JB. [FeFe]‐Hydrogenase: Defined Lysate‐Free Maturation Reveals a Key Role for Lipoyl‐H‐Protein in DTMA Ligand Biosynthesis. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202203413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Adrien Pagnier
- Department of Chemistry & Biochemistry Montana State University Bozeman MT 59717 USA
| | - Batuhan Balci
- Department of Chemistry & Biochemistry Montana State University Bozeman MT 59717 USA
| | - Eric M. Shepard
- Department of Chemistry & Biochemistry Montana State University Bozeman MT 59717 USA
| | - Hao Yang
- Department of Chemistry Northwestern University Evanston IL 60208 USA
| | - Douglas M. Warui
- Department of Chemistry The Pennsylvania State University University Park PA 16802 USA
| | - Stella Impano
- Department of Chemistry & Biochemistry Montana State University Bozeman MT 59717 USA
| | - Squire J. Booker
- Department of Chemistry The Pennsylvania State University University Park PA 16802 USA
- Howard Hughes Medical Institute Chevy Chase MD 20815 USA
| | - Brian M. Hoffman
- Department of Chemistry Northwestern University Evanston IL 60208 USA
| | - William E. Broderick
- Department of Chemistry & Biochemistry Montana State University Bozeman MT 59717 USA
| | - Joan B. Broderick
- Department of Chemistry & Biochemistry Montana State University Bozeman MT 59717 USA
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15
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Britt RD, Tao L, Rao G, Chen N, Wang LP. Proposed Mechanism for the Biosynthesis of the [FeFe] Hydrogenase H-Cluster: Central Roles for the Radical SAM Enzymes HydG and HydE. ACS BIO & MED CHEM AU 2022; 2:11-21. [PMID: 35187536 PMCID: PMC8855341 DOI: 10.1021/acsbiomedchemau.1c00035] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 10/08/2021] [Accepted: 10/11/2021] [Indexed: 01/05/2023]
Abstract
Radical S-adenosylmethionine (radical SAM or rSAM) enzymes use their S-adenosylmethionine cofactor bound to a unique Fe of a [4Fe-4S] cluster to generate the "hot" 5'-deoxyadenosyl radical, which drives highly selective radical reactions via specific interactions with a given rSAM enzyme's substrate. This Perspective focuses on the two rSAM enzymes involved in the biosynthesis of the organometallic H-cluster of [FeFe] hydrogenases. We present here a detailed sequential model initiated by HydG, which lyses a tyrosine substrate via a 5'-deoxyadenosyl H atom abstraction from those amino acid's amino group, initially producing dehydroglycine and an oxidobenzyl radical. In this model, two successive radical cascade reactions lead ultimately to the formation of HydG's product, a mononuclear Fe organometallic complex: [Fe(II)(CN)(CO)2(cysteinate)]-, with the iron originating from a unique "dangler" Fe coordinated by a cysteine ligand providing a sulfur bridge to another [4Fe-4S] auxiliary cluster in the enzyme. In turn, in this model, [Fe(II)(CN)(CO)2(cysteinate)]- is the substrate for HydE, the second rSAM enzyme in the biosynthetic pathway, which activates this mononuclear organometallic unit for dimerization, forming a [Fe2S2(CO)4(CN)2] precursor to the [2Fe] H component of the H-cluster, requiring only the completion of the bridging azadithiolate (SCH2NHCH2S) ligand. This model is built upon a foundation of data that incorporates cell-free synthesis, isotope sensitive spectroscopies, and the selective use of synthetic complexes substituting for intermediates in the enzymatic "assembly line". We discuss controversies pertaining to this model and some remaining open issues to be addressed by future work.
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Affiliation(s)
- R David Britt
- Department of Chemistry, University of California, Davis, Davis, California 95616, United States
| | - Lizhi Tao
- Department of Chemistry, University of California, Davis, Davis, California 95616, United States
| | - Guodong Rao
- Department of Chemistry, University of California, Davis, Davis, California 95616, United States
| | - Nanhao Chen
- Department of Chemistry, University of California, Davis, Davis, California 95616, United States
| | - Lee-Ping Wang
- Department of Chemistry, University of California, Davis, Davis, California 95616, United States
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16
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Donnan PH, Mansoorabadi SO. Broken-Symmetry Density Functional Theory Analysis of the Ω Intermediate in Radical S-Adenosyl-l-methionine Enzymes: Evidence for a Near-Attack Conformer over an Organometallic Species. J Am Chem Soc 2022; 144:3381-3385. [PMID: 35170316 DOI: 10.1021/jacs.2c00678] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Radical S-adenosyl-l-methionine (SAM) enzymes are found in all domains of life and catalyze a wide range of biochemical reactions. Recently, an organometallic intermediate, Ω, has been experimentally implicated in the 5'-deoxyadenosyl radical generation mechanism of the radical SAM superfamily. In this work, we employ broken-symmetry density functional theory to evaluate several structural models of Ω. The results show that the calculated hyperfine coupling constants (HFCCs) for the proposed organometallic structure of Ω are inconsistent with the experiment. In contrast, a near-attack conformer of SAM bound to the catalytic [4Fe-4S] cluster, in which the distance between the unique iron and SAM sulfur is ∼3 Å, yields HFCCs that are all within 1 MHz of the experimental values. These results clarify the structure of the ubiquitous Ω intermediate and suggest a paradigm shift reversal regarding the mechanism of SAM cleavage by members of the radical SAM superfamily.
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Affiliation(s)
- Patrick H Donnan
- Department of Chemistry and Biochemistry, Auburn University, 179 Chemistry Building, Auburn, Alabama 36849, United States
| | - Steven O Mansoorabadi
- Department of Chemistry and Biochemistry, Auburn University, 179 Chemistry Building, Auburn, Alabama 36849, United States
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17
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Nicolet Y, Cherrier MV, Amara P. Radical SAM Enzymes and Metallocofactor Assembly: A Structural Point of View. ACS BIO & MED CHEM AU 2022; 2:36-52. [PMID: 37102176 PMCID: PMC10114646 DOI: 10.1021/acsbiomedchemau.1c00044] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
This Review focuses on the structure-function relationship of radical S-adenosyl-l-methionine (SAM) enzymes involved in the assembly of metallocofactors corresponding to the active sites of [FeFe]-hydrogenase and nitrogenase [MoFe]-protein. It does not claim to correspond to an extensive review on the assembly machineries of these enzyme active sites, for which many good reviews are already available, but instead deals with the contribution of structural data to the understanding of their chemical mechanism (Buren et al. Chem. Rev.2020, 142 ( (25), ) 11006-11012; Britt et al. Chem. Sci.2020, 11 ( (38), ), 10313-10323). Hence, we will present the history and current knowledge about the radical SAM maturases HydE, HydG, and NifB as well as what, in our opinion, should be done in the near future to overcome the existing barriers in our understanding of this fascinating chemistry that intertwine organic radicals and organometallic complexes.
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Affiliation(s)
- Yvain Nicolet
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Metalloproteins Unit, F-38000 Grenoble, France
| | - Mickael V. Cherrier
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Metalloproteins Unit, F-38000 Grenoble, France
| | - Patricia Amara
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Metalloproteins Unit, F-38000 Grenoble, France
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18
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Zhang Y, Tao L, Woods TJ, Britt RD, Rauchfuss TB. Organometallic Fe 2(μ-SH) 2(CO) 4(CN) 2 Cluster Allows the Biosynthesis of the [FeFe]-Hydrogenase with Only the HydF Maturase. J Am Chem Soc 2022; 144:1534-1538. [PMID: 35041427 PMCID: PMC9169013 DOI: 10.1021/jacs.1c12506] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The biosynthesis of the active site of the [FeFe]-hydrogenases (HydA1), the H-cluster, is of interest because these enzymes are highly efficient catalysts for the oxidation and production of H2. The biosynthesis of the [2Fe]H subcluster of the H-cluster proceeds from simple precursors, which are processed by three maturases: HydG, HydE, and HydF. Previous studies established that HydG produces an Fe(CO)2(CN) adduct of cysteine, which is the substrate for HydE. In this work, we show that by using the synthetic cluster [Fe2(μ-SH)2(CN)2(CO)4]2- active HydA1 can be biosynthesized without maturases HydG and HydE.
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Affiliation(s)
- Yu Zhang
- School of Chemical Sciences, University of Illinois at Urbana─Champaign, Urbana, Illinois 61801, United States
| | - Lizhi Tao
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Toby J Woods
- School of Chemical Sciences, University of Illinois at Urbana─Champaign, Urbana, Illinois 61801, United States
| | - R David Britt
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Thomas B Rauchfuss
- School of Chemical Sciences, University of Illinois at Urbana─Champaign, Urbana, Illinois 61801, United States
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19
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Unusual structures and unknown roles of FeS clusters in metalloenzymes seen from a resonance Raman spectroscopic perspective. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2021.214287] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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20
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Rao G, Chen N, Marchiori DA, Wang LP, Britt RD. Accumulation and Pulse Electron Paramagnetic Resonance Spectroscopic Investigation of the 4-Oxidobenzyl Radical Generated in the Radical S-Adenosyl-l-methionine Enzyme HydG. Biochemistry 2022; 61:107-116. [PMID: 34989236 DOI: 10.1021/acs.biochem.1c00619] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The radical S-adenosyl-l-methionine (SAM) enzyme HydG cleaves tyrosine to generate CO and CN- ligands of the [FeFe] hydrogenase H-cluster, accompanied by the formation of a 4-oxidobenzyl radical (4-OB•), which is the precursor to the HydG p-cresol byproduct. Native HydG only generates a small amount of 4-OB•, limiting detailed electron paramagnetic resonance (EPR) spectral characterization beyond our initial EPR lineshape study employing various tyrosine isotopologues. Here, we show that the concentration of trapped 4-OB• is significantly increased in reactions using HydG variants, in which the "dangler Fe" to which CO and CN- bind is missing or substituted by a redox-inert Zn2+ ion. This allows for the detailed characterization of 4-OB• using high-field EPR and electron nuclear double resonance spectroscopy to extract its g-values and 1H/13C hyperfine couplings. These results are compared to density functional theory-predicted values of several 4-OB• models with different sizes and protonation states, with a best fit to the deprotonated radical anion configuration of 4-OB•. Overall, our results depict a clearer electronic structure of the transient 4-OB• radical and provide new insights into the radical SAM chemistry of HydG.
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Affiliation(s)
- Guodong Rao
- Department of Chemistry, University of California Davis, Davis, California 95616, United States
| | - Nanhao Chen
- Department of Chemistry, University of California Davis, Davis, California 95616, United States
| | - David A Marchiori
- Department of Chemistry, University of California Davis, Davis, California 95616, United States
| | - Lee-Ping Wang
- Department of Chemistry, University of California Davis, Davis, California 95616, United States
| | - R David Britt
- Department of Chemistry, University of California Davis, Davis, California 95616, United States
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21
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Chen N, Rao G, Britt RD, Wang LP. Quantum Chemical Study of a Radical Relay Mechanism for the HydG-Catalyzed Synthesis of a Fe(II)(CO) 2(CN)cysteine Precursor to the H-Cluster of [FeFe] Hydrogenase. Biochemistry 2021; 60:3016-3026. [PMID: 34569243 DOI: 10.1021/acs.biochem.1c00379] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The [FeFe] hydrogenase catalyzes the redox interconversion of protons and H2 with a Fe-S "H-cluster" employing CO, CN, and azadithiolate ligands to two Fe centers. The biosynthesis of the H-cluster is a highly interesting reaction carried out by a set of Fe-S maturase enzymes called HydE, HydF, and HydG. HydG, a member of the radical S-adenosylmethionine (rSAM) family, converts tyrosine, cysteine, and Fe(II) into an organometallic Fe(II)(CO)2(CN)cysteine "synthon", which serves as the substrate for HydE. Although key aspects of the HydG mechanism have been experimentally determined via isotope-sensitive spectroscopic methods, other important mechanistic questions have eluded experimental determination. Here, we use computational quantum chemistry to refine the mechanism of the HydG catalytic reaction. We utilize quantum mechanics/molecular mechanics simulations to investigate the reactions at the canonical Fe-S cluster, where a radical cleavage of the tyrosine substrate takes place and proceeds through a relay of radical intermediates to form HCN and a COO•- radical anion. We then carry out a broken-symmetry density functional theory study of the reactions at the unusual five-iron auxiliary Fe-S cluster, where two equivalents of CN- and COOH• coordinate to the fifth "dangler iron" in a series of substitution and redox reactions that yield the synthon as the final product for further processing by HydE.
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Affiliation(s)
- Nanhao Chen
- Department of Chemistry, University of California Davis, Davis, California 95616, United States
| | - Guodong Rao
- Department of Chemistry, University of California Davis, Davis, California 95616, United States
| | - R David Britt
- Department of Chemistry, University of California Davis, Davis, California 95616, United States
| | - Lee-Ping Wang
- Department of Chemistry, University of California Davis, Davis, California 95616, United States
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22
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Britt RD, Rauchfuss TB. Biosynthesis of the [FeFe] hydrogenase H-cluster via a synthetic [Fe(II)(CN)(CO) 2(cysteinate)] - complex. Dalton Trans 2021; 50:12386-12391. [PMID: 34545884 DOI: 10.1039/d1dt02258j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The H-cluster of [Fe-Fe] hydrogenase consists of a [4Fe]H subcluster linked by the sulfur of a cysteine residue to an organometallic [2Fe]H subcluster that utilizes terminal CO and CN ligands to each Fe along with a bridging CO and a bridging SCH2NHCH2S azadithiolate (adt) to catalyze proton reduction or hydrogen oxidation. Three Fe-S "maturase" proteins, HydE, HydF, and HydG, are responsible for the biosynthesis of the [2Fe]H subcluster and its incorporation into the hydrogenase enzyme to form this catalytically active H-cluster. We have proposed that HydG is a bifunctional enzyme that uses S-adenosylmethione (SAM) bound to a [4Fe-4S] cluster to lyse tyrosine via a transient 5'-deoxyadenosyl radical to produce CO and CN ligands to a unique cysteine-chelated Fe(II) that is linked to a second [4Fe-4S] cluster via the cysteine sulfur. In this "synthon model", after two cycles of tyrosine lysis, the product of HydG is completed: a [Fe(CN)(CO)2(cysteinate)]- organometallic unit that is vectored directly into the synthesis of the [2Fe]H sub-cluster. However our HydG-centric synthon model is not universally accepted, so further validation is important. In this Frontiers article, we discuss recent results using a synthetic "Syn-B" complex that donates [Fe(CN)(CO)2(cysteinate)]- units that match our proposed HydG product. Can Syn-B activate hydrogenase in the absence of HydG and its tyrosine substrate? If so, since Syn-B can be synthesized with specific magnetic nuclear isotopes and with chemical substitutions, its use could allow its enzymatic conversions on the route to the H-cluster to be monitored and modeled in fresh detail.
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Affiliation(s)
- R David Britt
- Department of Chemistry, University of California Davis, Davis, CA 95616, USA.
| | - Thomas B Rauchfuss
- School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
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