N5-CAIR mutase: role of a CO2 binding site and substrate movement in catalysis.

@article{Hoskins2007N5CAIRMR,
  title={N5-CAIR mutase: role of a CO2 binding site and substrate movement in catalysis.},
  author={Aaron A. Hoskins and Mariya Morar and T. Joseph Kappock and Irimpan I Mathews and Judith B. Zaugg and Timothy E Barder and Paul Peng and Akimitsu Okamoto and Steven E. Ealick and Joanne Stubbe},
  journal={Biochemistry},
  year={2007},
  volume={46 10},
  pages={2842-55}
}
N5-Carboxyaminoimidazole ribonucleotide mutase (N5-CAIR mutase or PurE) from Escherichia coli catalyzes the reversible interconversion of N5-CAIR to carboxyaminoimidazole ribonucleotide (CAIR) with direct CO2 transfer. Site-directed mutagenesis, a pH-rate profile, DFT calculations, and X-ray crystallography together provide new insight into the mechanism of this unusual transformation. These studies suggest that a conserved, protonated histidine (His45) plays an essential role in catalysis. The… CONTINUE READING