Catabolic Reductive Dehalogenase Substrate Complex Structures Underpin Rational Repurposing of Substrate Scope.
Halliwell, T., Fisher, K., Payne, K.A.P., Rigby, S.E.J., Leys, D.(2020) Microorganisms 8
- PubMed: 32887524 
- DOI: https://doi.org/10.3390/microorganisms8091344
- Primary Citation of Related Structures:  
6ZXU, 6ZXX, 6ZY0, 6ZY1 - PubMed Abstract: 
Reductive dehalogenases are responsible for the reductive cleavage of carbon-halogen bonds during organohalide respiration. A variety of mechanisms have been proposed for these cobalamin and [4Fe-4S] containing enzymes, including organocobalt, radical, or cobalt-halide adduct based catalysis. The latter was proposed for the oxygen-tolerant Nitratireductor pacificus pht-3B cataboli c reductive dehalogenase (NpRdhA). Here, we present the first substrate bound NpRdhA crystal structures, confirming a direct cobalt-halogen interaction is established and providing a rationale for substrate preference. Product formation is observed in crystallo due to X-ray photoreduction. Protein engineering enables rational alteration of substrate preference, providing a future blue print for the application of this and related enzymes in bioremediation.
Organizational Affiliation: 
Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.