Deciphering Radical Transport
in the Large Subunit
of Class I Ribonucleotide Reductase
Patrick
G. Holder
Arturo A. Pizano
Bryce L. Anderson
JoAnne Stubbe
Daniel G. Nocera
10.1021/ja209016j.s002
https://acs.figshare.com/articles/dataset/Deciphering_Radical_Transport_in_the_Large_Subunit_of_Class_I_Ribonucleotide_Reductase/2558422
Incorporation of 2,3,6-trifluorotyrosine (F<sub>3</sub>Y) and a
rhenium bipyridine ([Re]) photooxidant into a peptide corresponding
to the <i>C</i>-terminus of the β protein (βC19)
of Escherichia coli ribonucleotide
reductase (RNR) allows for the temporal monitoring of radical transport
into the α2 subunit of RNR. Injection of the photogenerated
F<sub>3</sub>Y radical from the [Re]–F<sub>3</sub>Y−βC19
peptide into the surface accessible Y731 of the α2 subunit is
only possible when the second Y730 is present. With the Y–Y
established, radical transport occurs with a rate constant of 3 ×
10<sup>5</sup> s<sup>–1</sup>. Point mutations that disrupt
the Y–Y dyad shut down radical transport. The ability to obviate
radical transport by disrupting the hydrogen bonding network of the
amino acids composing the colinear proton-coupled electron transfer
pathway in α2 suggests a finely tuned evolutionary adaptation
of RNR to control the transport of radicals in this enzyme.
2012-01-18 00:00:00
Deciphering Radical Transport
Re
photogenerated F 3Y
peptide
RNR
α2 subunit
Escherichia coli ribonucleotide reductase