The Bacillus anthracis class Ib ribonucleotide reductase subunit NrdF intrinsically selects manganese over iron.

The Bacillus anthracis class Ib ribonucleotide reductase subunit NrdF intrinsically selects manganese over iron.
J Biol Inorg Chem. 2020 Apr 15;:
Authors: Grāve K, Griese JJ, Berggren G, Bennett MD, Högbom M
Abstract
Correct protein metallation in the complex mixture of the cell is a prerequisite for metalloprotein function. While some metals, such as Cu, are commonly chaperoned, specificity towards metals earlier in the Irving-Williams series is achieved through other means, the determinants of which are poorly understood. The dimetal carboxylate family of proteins provides an intriguing example, as different proteins, while sharing a common fold and the same 4-carboxylate 2-histidine coordination sphere, are known to require either a Fe/Fe, Mn/Fe or Mn/Mn cofactor for function. We previously showed that the R2lox proteins from this family spontaneously assemble the heterodinuclear Mn/Fe cofactor. Here we show that the class Ib ribonucleotide reductase R2 protein from Bacillus anthracis spontaneously assembles a Mn/Mn cofactor in vitro, under both aerobic and anoxic conditions, when the metal-free protein is subjected to incubation with MnII and FeII in equal concentrations. This observation provides an example of a protein scaffold intrinsically predisposed to defy the Irving-Williams series and supports the assumption that the Mn/Mn cofactor is the biologically relevant cofactor in vivo. Substitution of a second coordination sph...

Source: Journal of Biological Inorganic Chemistry : JBIC - April 14, 2020 Category: Chemistry Authors: Grāve K, Griese JJ, Berggren G, Bennett MD, Högbom M Tags: J Biol Inorg Chem Source Type: research