The Crystal Structure of <i>Thermotoga maritima - Fig 2 </i> Class III Ribonucleotide Reductase Lacks a Radical Cysteine Pre-Positioned in the Active Site

<p>a) Details of the conformation of the glycyl radical and finger loops in the active site of tmNrdD. The two loops are shown as sticks with the surrounding <b>β</b>-barrel as a cartoon. A 2m|Fo|-D|Fc| omit electron density map is shown contoured at 1.0 σ. The map was calculated by omitting residues 351–364 and 618–623 from the model followed by three macrocycles of torsion angle molecular dynamics in phenix.refine with default parameters. b) Cross-eyed stereo view comparing the glycyl radical loops in several representative glycyl radical enzymes. tmNrdD is shown in red, T4NrdD in blue, pyruvate formate lyase in magenta, glycerol dehydratase in green and 4-hydroxyphenylacetate decarboxylase in orange. The C<b>α</b> atom of Gly621 in tmNrdD is indicated with a red sphere.