{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Rumbaugh TD"],"funding":["U.S. Department of Energy","U.S. Department of Energy (DOE)","National Science Foundation (NSF)","National Science Foundation"],"pagination":["e2400267121"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC11348241"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["121(34)"],"pubmed_abstract":["The fusion of hydrogenases and photosynthetic reaction centers (RCs) has proven to be a promising strategy for the production of sustainable biofuels. Type I (iron-sulfur-containing) RCs, acting as photosensitizers, are capable of promoting electrons to a redox state that can be exploited by hydrogenases for the reduction of protons to dihydrogen (H<sub>2</sub>). While both [FeFe] and [NiFe] hydrogenases have been used successfully, they tend to be limited due to either O<sub>2</sub> sensitivity, binding specificity, or H<sub>2</sub> production rates. In this study, we fuse a peripheral (stromal) subunit of Photosystem I (PS I), PsaE, to an O<sub>2</sub>-tolerant [FeFe] hydrogenase from <i>Clostridium beijerinckii</i> using a flexible [GGS]<sub>4</sub> linker group (<i>Cb</i>HydA1-PsaE). We demonstrate that the <i>Cb</i>HydA1 chimera can be synthetically activated in vitro to show bidirectional activity and that it can be quantitatively bound to a PS I variant lacking the PsaE subunit. When illuminated in an anaerobic environment, the nanoconstruct generates H<sub>2</sub> at a rate of 84.9 ± 3.1 µmol H<sub>2</sub> mg<sub>chl</sub><sup>-1</sup> h<sup>-1</sup>. Further, when prepared and illuminated in the presence of O<sub>2</sub>, the nanoconstruct retains the ability to generate H<sub>2</sub>, though at a diminished rate of 2.2 ± 0.5 µmol H<sub>2</sub> mg<sub>chl</sub><sup>-1</sup> h<sup>-1</sup>. This demonstrates not only that PsaE is a promising scaffold for PS I-based nanoconstructs, but the use of an O<sub>2</sub>-tolerant [FeFe] hydrogenase opens the possibility for an in vivo H<sub>2</sub> generating system that can function in the presence of O<sub>2</sub>."],"journal":["Proceedings of the National Academy of Sciences of the United States of America"],"pubmed_title":["Light-induced H<sub>2</sub> generation in a photosystem I-O<sub>2</sub>-tolerant [FeFe] hydrogenase nanoconstruct."],"pmcid":["PMC11348241"],"funding_grant_id":["DE-SC0018087","CHE-1943748"],"pubmed_authors":["Silakov A","Baker CS","Rumbaugh TD","Golbeck JH","Gorka MJ"],"additional_accession":[]},"is_claimable":false,"name":"Light-induced H<sub>2</sub> generation in a photosystem I-O<sub>2</sub>-tolerant [FeFe] hydrogenase nanoconstruct.","description":"The fusion of hydrogenases and photosynthetic reaction centers (RCs) has proven to be a promising strategy for the production of sustainable biofuels. Type I (iron-sulfur-containing) RCs, acting as photosensitizers, are capable of promoting electrons to a redox state that can be exploited by hydrogenases for the reduction of protons to dihydrogen (H<sub>2</sub>). While both [FeFe] and [NiFe] hydrogenases have been used successfully, they tend to be limited due to either O<sub>2</sub> sensitivity, binding specificity, or H<sub>2</sub> production rates. In this study, we fuse a peripheral (stromal) subunit of Photosystem I (PS I), PsaE, to an O<sub>2</sub>-tolerant [FeFe] hydrogenase from <i>Clostridium beijerinckii</i> using a flexible [GGS]<sub>4</sub> linker group (<i>Cb</i>HydA1-PsaE). We demonstrate that the <i>Cb</i>HydA1 chimera can be synthetically activated in vitro to show bidirectional activity and that it can be quantitatively bound to a PS I variant lacking the PsaE subunit. When illuminated in an anaerobic environment, the nanoconstruct generates H<sub>2</sub> at a rate of 84.9 ± 3.1 µmol H<sub>2</sub> mg<sub>chl</sub><sup>-1</sup> h<sup>-1</sup>. Further, when prepared and illuminated in the presence of O<sub>2</sub>, the nanoconstruct retains the ability to generate H<sub>2</sub>, though at a diminished rate of 2.2 ± 0.5 µmol H<sub>2</sub> mg<sub>chl</sub><sup>-1</sup> h<sup>-1</sup>. This demonstrates not only that PsaE is a promising scaffold for PS I-based nanoconstructs, but the use of an O<sub>2</sub>-tolerant [FeFe] hydrogenase opens the possibility for an in vivo H<sub>2</sub> generating system that can function in the presence of O<sub>2</sub>.","dates":{"release":"2024-01-01T00:00:00Z","publication":"2024 Aug","modification":"2026-06-02T01:57:30.141Z","creation":"2025-04-04T00:05:11.762Z"},"accession":"S-EPMC11348241","cross_references":{"pubmed":["39136990"],"doi":["10.1073/pnas.2400267121"]}}