Fig. 5: MbnB active site.
a Electron density maps of three metal ions contoured with a 2Fo-Fc map at 5 σ in VcMbnB (left) and RrMbnB (right) structures. Fe atoms are colored in cyan (VcMbnB) and brown (RrMbnB). b Interaction networks formed by the tri-iron cluster with surrounding residues in VcMbnB (left) and RrMbnB (right). The six-coordinate Fe1II is highlighted as a cartoon in the middle. O2 occupies a water site for activation. Hydrogen bonds, Fe–S bonds, and Fe–Fe bonds are indicated by blue, yellow and pink dashed lines, respectively. W, water molecule. c In vitro activity of VcMbnBC or mutants to modify the synthetic VcMbnA (left); in vivo activity of RrMbnBC or mutants to modify the co-expressed RrMbnA (right). The relative absorbances at ~270 nm for VcMbnA and ~335 nm for RrMbnA are represented as histograms in the insets.
