Does the crystal structure of vanadium nitrogenase contain a reaction intermediate? Evidence from quantum refinement.

ABSTRACT: Recently, a crystal structure of V-nitrogenase was presented, showing that one of the µ₂ sulphide ions in the active site (S2B) is replaced by a lighter atom, suggested to be NH or NH₂, i.e. representing a reaction intermediate. Moreover, a sulphur atom is found 7 Å from the S2B site, suggested to represent a storage site for this ion when it is displaced. We have re-evaluated this structure with quantum refinement, i.e. standard crystallographic refinement in which the empirical restraints (employed to ensure that the final structure makes chemical sense) are replaced by more accurate quantum-mechanical calculations. This allows us to test various interpretations of the structure, employing quantum-mechanical calculations to predict the ideal structure and to use cry

SUBMITTER: Cao L 

PROVIDER: S-EPMC7511287 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature