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

Abstract

Background: S. cerevisiae ribonucleotide reductase (RNR) comprises ␣ and ␤␤Ј subunits in an (␣ 2 ) m (␤␤Ј) n active holoenzyme. Results: C-terminal tail mutants of ␤␤Ј prevent radical transfer across the ␣-␤ interface and consequently deoxynucleotide production in vivo. Conclusion:The ␤␤Ј C-terminal tails interact only with the proximal ␣ within each ␣/␤(␣/␤Ј) pair. Significance: The predisposition of the ␤␤Ј C-terminal tails in active RNR in vivo is established.

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

“…Finally, the mechanism of PCET across the subunit interface observed with the E. coli RNR is likely to be conserved in all class I RNRs based on their subunit structures and the conserved weak subunit associations dictated by the C-terminal tail of β2. 70 , 71 The pathway for oxidation is conserved between RNR classes Ia, Ib and Ic, as is the regulation of the pathway by NDP/effector binding. 72 Thus, while the “details” of the radical transfer mechanism might be different in the individual class I RNRs, general principles will likely emerge from the studies on E. coli RNR, given all of the evolutionarily conserved features.…”

Redox-Dependent Structural Coupling between the α2 and β2 Subunits in E. coli Ribonucleotide Reductase

“…16,40 This C-terminal domain interacts with the α2 subunit. 76 Recently, it was shown that Y356 has a relative…”

“…This suggestion that Y x is conformationally flexible in the QC may be consistent with an assignment to Y356 in β2. Y356 is located in a C-terminal domain of β2 that is not resolved in the crystal structure. , This C-terminal domain interacts with the α2 subunit . Recently, it was shown that Y356 has a relative redox potential, which is (∼100 mV) lower than the active site cysteine in α2 .…”

Convergent Allostery in Ribonucleotide Reductase

“…1a). The flexible Cterminus of β plays a critical role in this process by binding to α and contributing a conserved tyrosine along the RT pathway [13][14][15][16] ( Supplementary Fig. 1c).…”