Radical Initiation in the Class I Ribonucleotide Reductase:  Long-Range Proton-Coupled Electron Transfer?

2003 ◽  
Vol 103 (6) ◽  
pp. 2167-2202 ◽  
Author(s):  
JoAnne Stubbe ◽  
Daniel G. Nocera ◽  
Cyril S. Yee ◽  
Michelle C. Y. Chang
Keyword(s):  
Electron Transfer ◽  
Long Range ◽  
Ribonucleotide Reductase ◽  
Class I ◽  
Radical Initiation ◽  
Proton Coupled Electron Transfer

Radical Initiation in the Class I Ribonucleotide Reductase: Long-Range Proton-Coupled Electron Transfer?

ChemInform ◽  
2003 ◽  
Vol 34 (32) ◽  
Author(s):  
JoAnne Stubbe ◽  
Daniel G. Nocera ◽  
Cyril S. Yee ◽  
Michelle C. Y. Chang
Keyword(s):  
Electron Transfer ◽  
Long Range ◽  
Ribonucleotide Reductase ◽  
Class I ◽  
Radical Initiation ◽  
Proton Coupled Electron Transfer

Long-range proton-coupled electron transfer in the Escherichia coli class Ia ribonucleotide reductase

2017 ◽  
Vol 61 (2) ◽  
pp. 281-292 ◽  
Author(s):  
Steven Y. Reece ◽  
Mohammad R. Seyedsayamdost
Keyword(s):  
Escherichia Coli ◽  
Electron Transfer ◽  
Amino Acid ◽  
Long Range ◽  
Ribonucleotide Reductase ◽  
Unnatural Amino Acids ◽  
Radical Mechanism ◽  
Tyrosyl Radical ◽  
Proton Coupled Electron Transfer ◽  
Vis Spectroscopy

Escherichia coli class Ia ribonucleotide reductase (RNR) catalyzes the conversion of nucleotides to 2′-deoxynucleotides using a radical mechanism. Each turnover requires radical transfer from an assembled diferric tyrosyl radical (Y•) cofactor to the enzyme active site over 35 Å away. This unprecedented reaction occurs via an amino acid radical hopping pathway spanning two protein subunits. To study the mechanism of radical transport in RNR, a suite of biochemical approaches have been developed, such as site-directed incorporation of unnatural amino acids with altered electronic properties and photochemical generation of radical intermediates. The resulting variant RNRs have been investigated using a variety of time-resolved physical techniques, including transient absorption and stopped-flow UV-Vis spectroscopy, as well as rapid freeze-quench EPR, ENDOR, and PELDOR spectroscopic methods. The data suggest that radical transport occurs via proton-coupled electron transfer (PCET) and that the protein structure has evolved to manage the proton and electron transfer co-ordinates in order to prevent ‘off-pathway’ reactivity and build-up of oxidised intermediates. Thus, precise design and control over the factors that govern PCET is key to enabling reversible and long-range charge transport by amino acid radicals in RNR.

Proton-Coupled Electron Transfer Drives Long-Range Proton Translocation in Bioinspired Systems

2019 ◽  
Vol 141 (36) ◽  
pp. 14057-14061 ◽  
Author(s):  
Emmanuel Odella ◽  
Brian L. Wadsworth ◽  
S. Jimena Mora ◽  
Joshua J. Goings ◽  
Mioy T. Huynh ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Long Range ◽  
Proton Translocation ◽  
Proton Coupled Electron Transfer

scholarly journals Structural Basis for Superoxide Activation of Flavobacterium johnsoniae Class I Ribonucleotide Reductase and for Radical Initiation by Its Dimanganese Cofactor

Biochemistry ◽  
2018 ◽  
Vol 57 (18) ◽  
pp. 2679-2693 ◽  
Author(s):  
Hannah R. Rose ◽  
Manas K. Ghosh ◽  
Ailiena O. Maggiolo ◽  
Christopher J. Pollock ◽  
Elizabeth J. Blaesi ◽  
...  
Keyword(s):  
Ribonucleotide Reductase ◽  
Class I ◽  
Structural Basis ◽  
Radical Initiation ◽  
Flavobacterium Johnsoniae
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