Structure of plant Photosystem I-plastocyanin complex reveals strong hydrophobic interactions

Photosystem I is defined as plastocyanin-ferredoxin oxidoreductase. Taking advantage of genetic engineering, kinetic analyses and cryo-EM, our data provide novel mechanistic insights into binding and electron transfer between PSI and Pc. Structural data at 2.74 Å resolution reveals strong hydrophobic interactions in the plant PSI-Pc ternary complex, leading to exclusion of water molecules from PsaA-PsaB / Pc interface once the PSI-Pc complex forms. Upon oxidation of Pc, a slight tilt of bound oxidized Pc allows water molecules to accommodate the space between Pc and PSI to drive Pc dissociation. Such a scenario is consistent with the six times larger dissociation constant of oxidized as compared to reduced Pc and mechanistically explains how this molecular machine optimized electron transfer for fast turnover.

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Structure of plant PSI-plastocyanin complex reveals strong hydrophobic interactions

10.1101/2021.02.03.429574 ◽

2021 ◽

Author(s):

Ido Caspy ◽

Mariia Fadeeva ◽

Sebastian Kuhlgert ◽

Anna Borovikova-Sheinker ◽

Daniel Klaiman ◽

...

Keyword(s):

Electron Transfer ◽

Genetic Engineering ◽

Hydrophobic Interactions ◽

Structural Data ◽

Oxygenic Photosynthesis ◽

Water Molecules ◽

Major Step ◽

Ferredoxin Oxidoreductase ◽

Complex Forms ◽

Oxidized Pc

AbstractPhotosystem I is defined as plastocyanin-ferredoxin oxidoreductase. Taking advantage of genetic engineering, kinetic analyses and cryo-EM, our data provide novel mechanistic insights into binding and electron transfer between PSI and Pc. Structural data at 2.74 Å resolution reveals strong hydrophobic interactions in the plant PSI-Pc ternary complex, leading to exclusion of water molecules from PsaA-PsaB / Pc interface once the PSI-Pc complex forms. Upon oxidation of Pc, a slight tilt of bound oxidized Pc allows water molecules to accommodate the space between Pc and PSI to drive Pc dissociation. Such a scenario is consistent with the six times larger dissociation constant of oxidized as compared to reduced Pc and mechanistically explains how this molecular machine optimized electron transfer for fast turnover.One Sentence SummaryGenetic engineering, kinetics and cryo-EM structural data reveal a mechanism in a major step of oxygenic photosynthesis

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Role of Hydrophobic Interactions in the Flavodoxin Mediated Electron Transfer from Photosystem I to Ferredoxin-NADP+Reductase inAnabaenaPCC 7119†

Biochemistry ◽

10.1021/bi0270541 ◽

2003 ◽

Vol 42 (7) ◽

pp. 2036-2045 ◽

Cited By ~ 19

Author(s):

Isabel Nogués ◽

Marta Martínez-Júlvez ◽

José A. Navarro ◽

Manuel Hervás ◽

Lorena Armenteros ◽

...

Keyword(s):

Electron Transfer ◽

Photosystem I ◽

Hydrophobic Interactions ◽

Mediated Electron Transfer

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Reversible inhibition and reactivation of electron transfer in photosystem I

Photosynthesis Research ◽

10.1007/s11120-020-00760-9 ◽

2020 ◽

Vol 145 (2) ◽

pp. 97-109 ◽

Cited By ~ 1

Author(s):

Neva Agarwala ◽

Hiroki Makita ◽

Lujun Luo ◽

Wu Xu ◽

Gary Hastings

Keyword(s):

Electron Transfer ◽

Photosystem I ◽

Reversible Inhibition

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Jumping Ahead with Sleeping Beauty: Mechanistic Insights into Cut-and-Paste Transposition

Viruses ◽

10.3390/v13010076 ◽

2021 ◽

Vol 13 (1) ◽

pp. 76

Author(s):

Matthias T. Ochmann ◽

Zoltán Ivics

Keyword(s):

Genetic Engineering ◽

Structural Data ◽

Sleeping Beauty ◽

Preclinical Studies ◽

Gene Vector ◽

Functional Information ◽

Vector Systems ◽

Novel Variants ◽

Insight Into ◽

Cellular Genome

Sleeping Beauty (SB) is a transposon system that has been widely used as a genetic engineering tool. Central to the development of any transposon as a research tool is the ability to integrate a foreign piece of DNA into the cellular genome. Driven by the need for efficient transposon-based gene vector systems, extensive studies have largely elucidated the molecular actors and actions taking place during SB transposition. Close transposon relatives and other recombination enzymes, including retroviral integrases, have served as useful models to infer functional information relevant to SB. Recently obtained structural data on the SB transposase enable a direct insight into the workings of this enzyme. These efforts cumulatively allowed the development of novel variants of SB that offer advanced possibilities for genetic engineering due to their hyperactivity, integration deficiency, or targeting capacity. However, many aspects of the process of transposition remain poorly understood and require further investigation. We anticipate that continued investigations into the structure–function relationships of SB transposition will enable the development of new generations of transposition-based vector systems, thereby facilitating the use of SB in preclinical studies and clinical trials.

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