Spectroscopic Evidence for a H Bond Network at Y356 Located at the Subunit Interface of Active E. coli Ribonucleotide Reductase

Biochemistry ◽  
2017 ◽  
Vol 56 (28) ◽  
pp. 3647-3656 ◽  
Author(s):  
Thomas U. Nick ◽  
Kanchana R. Ravichandran ◽  
JoAnne Stubbe ◽  
Müge Kasanmascheff ◽  
Marina Bennati
Keyword(s):  
Ribonucleotide Reductase ◽  
Spectroscopic Evidence ◽  
E Coli ◽  
Subunit Interface ◽  
Bond Network

scholarly journals ENDOR Spectroscopy and DFT Calculations: Evidence for the Hydrogen-Bond Network Within α2 in the PCET of E. coli Ribonucleotide Reductase

2012 ◽  
Vol 134 (42) ◽  
pp. 17661-17670 ◽  
Author(s):  
Tomislav Argirević ◽  
Christoph Riplinger ◽  
JoAnne Stubbe ◽  
Frank Neese ◽  
Marina Bennati
Keyword(s):  
Hydrogen Bond ◽  
Dft Calculations ◽  
Ribonucleotide Reductase ◽  
Hydrogen Bond Network ◽  
E Coli ◽  
Endor Spectroscopy ◽  
Bond Network

scholarly journals Radical transfer in E. coli ribonucleotide reductase: a NH2Y731/R411A-α mutant unmasks a new conformation of the pathway residue 731

2016 ◽  
Vol 7 (3) ◽  
pp. 2170-2178 ◽  
Author(s):  
Müge Kasanmascheff ◽  
Wankyu Lee ◽  
Thomas U. Nick ◽  
JoAnne Stubbe ◽  
Marina Bennati
Keyword(s):  
Long Range ◽  
Ribonucleotide Reductase ◽  
E Coli ◽  
Subunit Interface ◽  
Radical Transfer

A new conformation of theE. coliRNR pathway residue 731 was trapped during long-range radical transfer across the αβ subunit interface.

scholarly journals Investigation of in Vivo Roles of the C-terminal Tails of the Small Subunit (ββ′) of Saccharomyces cerevisiae Ribonucleotide Reductase

2013 ◽  
Vol 288 (20) ◽  
pp. 13951-13959 ◽  
Author(s):  
Yan Zhang ◽  
Xiuxiang An ◽  
JoAnne Stubbe ◽  
Mingxia Huang
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ribonucleotide Reductase ◽  
Large Subunit ◽  
Small Subunit ◽  
Cluster Assembly ◽  
E Coli ◽  
Viability Assay ◽  
Docking Model

The small subunit (β2) of class Ia ribonucleotide reductase (RNR) houses a diferric tyrosyl cofactor (Fe2III-Y•) that initiates nucleotide reduction in the large subunit (α2) via a long range radical transfer (RT) pathway in the holo-(α2)m(β2)n complex. The C-terminal tails of β2 are predominantly responsible for interaction with α2, with a conserved tyrosine residue in the tail (Tyr356 in Escherichia coli NrdB) proposed to participate in cofactor assembly/maintenance and in RT. In the absence of structure of any holo-RNR, the role of the β tail in cluster assembly/maintenance and its predisposition within the holo-complex have remained unknown. In this study, we have taken advantage of the unusual heterodimeric nature of the Saccharomyces cerevisiae RNR small subunit (ββ′), of which only β contains a cofactor, to address both of these issues. We demonstrate that neither β-Tyr376 nor β′-Tyr323 (Tyr356 equivalent in NrdB) is required for cofactor assembly in vivo, in contrast to the previously proposed mechanism for E. coli cofactor maintenance and assembly in vitro. Furthermore, studies with reconstituted-ββ′ and an in vivo viability assay show that β-Tyr376 is essential for RT, whereas Tyr323 in β′ is not. Although the C-terminal tail of β′ is dispensable for cofactor formation and RT, it is essential for interactions with β and α to form the active holo-RNR. Together the results provide the first evidence of a directed orientation of the β and β′ C-terminal tails relative to α within the holoenzyme consistent with a docking model of the two subunits and argue against RT across the β β′ interface.

Specific inhibition of ribonucleotide reductases by peptides corresponding to the C-terminal of their second subunit

1991 ◽  
Vol 69 (1) ◽  
pp. 79-83 ◽  
Author(s):  
Gregory Cosentino ◽  
Pierre Lavallée ◽  
Sumanas Rakhit ◽  
Raymond Plante ◽  
Yvon Gaudette ◽  
...  
Keyword(s):  
Ribonucleotide Reductase ◽  
Synthetic Peptide ◽  
Herpes Virus ◽  
Small Subunit ◽  
Terminal Sequence ◽  
E Coli ◽  
Ribonucleotide Reductases ◽  
Human Enzyme ◽  
Bacterial Enzyme ◽  
Herpès Virus

Previous studies have shown that herpes virus ribonucleotide reductase can be inhibited by a synthetic nonapeptide whose sequence is identical to the C-terminal of the small subunit of the enzyme. This peptide is able to interfere with normal subunit association that takes place through the C-terminal of the small subunit. In this report, we illustrate that inhibition of ribonucleotide reductases by peptides corresponding to the C-terminal of subunit R2 is also observed for the enzyme isolated from Escherichia coli, hamster, and human cells. The nonapeptide corresponding to the bacterial C-terminal sequence was found to inhibit E. coli enzyme with an IC50 of 400 μM, while this peptide had no effect on mammalian ribonucleotide reductase. A corresponding synthetic peptide derived from the C-terminal of the small subunit of the human enzyme inhibited both human and hamster ribonucleotide reductases with IC50 values of 160 and 120 μM, respectively. However, this peptide had no inhibitory activity against the bacterial enzyme. Equivalent peptides derived from herpes virus ribonucleotide reductase had no effect on either the bacterial or mammalian enzymes. Thus, subunit association at the C-terminal of the small subunit appears to be a common feature of ribonucleotide reductases. In addition, the inhibitory phenomenon observed with peptides corresponding to the C-terminal appears not only to be universal, but also specific to the primary sequence of the enzyme.Key words: ribonucleotide reductase, inhibition, human, bacteria.

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