Class Id ribonucleotide reductase utilizes a Mn₂(IV,III) cofactor and undergoes large conformational changes on metal loading.

ABSTRACT: Outside of the photosynthetic machinery, high-valent manganese cofactors are rare in biology. It was proposed that a recently discovered subclass of ribonucleotide reductase (RNR), class Id, is dependent on a Mn₂(IV,III) cofactor for catalysis. Class I RNRs consist of a substrate-binding component (NrdA) and a metal-containing radical-generating component (NrdB). Herein we utilize a combination of EPR spectroscopy and enzyme assays to underscore the enzymatic relevance of the Mn₂(IV,III) cofactor in class Id NrdB from Facklamia ignava. Once formed, the Mn₂(IV,III) cofactor confers enzyme activity that correlates well with cofactor quantity. Moreover, we present the X-ray structure of the apo- and aerobically Mn-loaded forms of the homologous class Id NrdB f

SUBMITTER: Rozman Grinberg I 

PROVIDER: S-EPMC6754362 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature