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 ◽  
...  
ChemInform ◽  
2003 ◽  
Vol 34 (32) ◽  
Author(s):  
JoAnne Stubbe ◽  
Daniel G. Nocera ◽  
Cyril S. Yee ◽  
Michelle C. Y. Chang

2021 ◽  
Vol 8 ◽  
Author(s):  
Mahmudul Hasan ◽  
Ipsita Banerjee ◽  
Inna Rozman Grinberg ◽  
Britt-Marie Sjöberg ◽  
Derek T. Logan

The essential enzyme ribonucleotide reductase (RNR) is highly regulated both at the level of overall activity and substrate specificity. Studies of class I, aerobic RNRs have shown that overall activity is downregulated by the binding of dATP to a small domain known as the ATP-cone often found at the N-terminus of RNR subunits, causing oligomerization that prevents formation of a necessary α2β2 complex between the catalytic (α2) and radical generating (β2) subunits. In some relatively rare organisms with RNRs of the subclass NrdAi, the ATP-cone is found at the N-terminus of the β subunit rather than more commonly the α subunit. Binding of dATP to the ATP-cone in β results in formation of an unusual β4 tetramer. However, the structural basis for how the formation of the active complex is hindered by such oligomerization has not been studied. Here we analyse the low-resolution three-dimensional structures of the separate subunits of an RNR from subclass NrdAi, as well as the α4β4 octamer that forms in the presence of dATP. The results reveal a type of oligomer not previously seen for any class of RNR and suggest a mechanism for how binding of dATP to the ATP-cone switches off catalysis by sterically preventing formation of the asymmetrical α2β2 complex.


2003 ◽  
Vol 103 (6) ◽  
pp. 2167-2202 ◽  
Author(s):  
JoAnne Stubbe ◽  
Daniel G. Nocera ◽  
Cyril S. Yee ◽  
Michelle C. Y. Chang

2009 ◽  
Vol 131 (34) ◽  
pp. 12155-12171 ◽  
Author(s):  
Kasper P. Jensen ◽  
Caleb B. Bell, ◽  
Michael D. Clay ◽  
Edward I. Solomon

Biochemistry ◽  
2019 ◽  
Vol 58 (50) ◽  
pp. 5074-5084 ◽  
Author(s):  
Brandon L. Greene ◽  
JoAnne Stubbe ◽  
Daniel G. Nocera

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Julie-Anne Gandier ◽  
David N. Langelaan ◽  
Amy Won ◽  
Kylie O’Donnell ◽  
Julie L. Grondin ◽  
...  

2015 ◽  
Vol 119 (43) ◽  
pp. 13777-13784 ◽  
Author(s):  
Jovan Livada ◽  
Ryan J. Martinie ◽  
Laura M. K. Dassama ◽  
Carsten Krebs ◽  
J. Martin Bollinger ◽  
...  

2001 ◽  
Vol 75 (4) ◽  
pp. 1672-1680 ◽  
Author(s):  
John L. Foster ◽  
Rene P. Molina ◽  
Tianci Luo ◽  
Vivek K. Arora ◽  
Yaoxing Huang ◽  
...  

ABSTRACT We have characterized the functional integrity of seven primary Nef isolates: five from a long-term nonprogressing human immunodeficiency virus (HIV)-infected individual and one each from two patients with AIDS. One of the seven Nefs was defective for CD4 downregulation, two others were defective for PAK-2 activation, and one Nef was defective for PAK-2 activation and major histocompatibility complex (MHC) class I downregulation. Five of the Nefs were tested and found to be functional for the enhancement of virus particle infectivity. The structural basis for each of the functional defects has been analyzed by constructing a consensus nef, followed by mutational analysis of the variant amino acid residues. Mutations A29V and F193I were deleterious to CD4 downregulation and PAK-2 activation, respectively, while S189R rendered Nef defective for both MHC class I downregulation and PAK-2 activation. A search of the literature identified HIVs from five patients with Nefs predominantly mutated at F193 and from one patient with Nefs predominantly mutated at A29. A29 is highly conserved in all HIV subtypes except for subtype E. F193 is conserved in subtype B (and possibly in the closely related subtype D), but none of the other HIV group M subtypes. Our results suggest that functional distinctions may exist between HIV subtypes.


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