Cysteine-mediated decyanation of vitamin B12 by the predicted membrane transporter BtuM.Rempel, S., Colucci, E., de Gier, J.W., Guskov, A., Slotboom, D.J.
(2018) Nat Commun 9: 3038-3038
- PubMed: 30072686
- DOI: https://doi.org/10.1038/s41467-018-05441-9
- Primary Citation of Related Structures:
- PubMed Abstract:
Uptake of vitamin B12 is essential for many prokaryotes, but in most cases the membrane proteins involved are yet to be identified. We present the biochemical characterization and high-resolution crystal structure of BtuM, a predicted bacterial vitamin B12 uptake system. BtuM binds vitamin B12 in its base-off conformation, with a cysteine residue as axial ligand of the corrin cobalt ion. Spectroscopic analysis indicates that the unusual thiolate coordination allows for decyanation of vitamin B12. Chemical modification of the substrate is a property other characterized vitamin B12-transport proteins do not exhibit.
Department of Biochemistry and Biophysics, Stockholm University, 10691, Stockholm, Sweden.