I ribonucleotide ReductaseoThe Radical Transfer Pathway

CLASS I RIBONUCLEOTIDE REDUCTASEoTHE RADICAL TRANSFER PATHWAY 

FIGURE 4. The class I RNR holoenzyme complex model built from the separately solved three-dimensional structures of E. coli protein R1 (Uhlin and Eklund, 1994) and protein R2 (Nordlund and Eklund, 1993 Nordlund et ai, 1990). The path of the radical transfer is indicated, and a blow-up of the participating residues and a substrate nucleotide is shown in the box. 

coli R2 Y122F Catalytically inert, native iron site, no radical c 

Mouse R2 Y177F/CAV All catalytically inert, changed iron site, no Tyr (Phel77/Cysl77), Tyr (Trpl77)  

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