Download MendeleyOpen-closed conformational change revealed by the crystal structures of 3-keto-L-gulonate 6-phosphate decarboxylase from Streptococcus mutans
Li, G.L., Liu, X., Nan, J., Brostromer, E., Li, L.F., Su, X.D.(2009) Biochem Biophys Res Commun 381: 429-433
- PubMed: 19222992
- DOI: https://doi.org/10.1016/j.bbrc.2009.02.049
- Primary Citation of Related Structures:
3EXR, 3EXS, 3EXT - PubMed Abstract:
The 3-keto-L-gulonate 6-phosphate decarboxylase (KGPDC) catalyses the decarboxylation of 3-keto-L-gulonate 6-phosphate to L-xylulose in the presence of magnesium ions. The enzyme is involved in L-ascorbate metabolism and plays an essential role in the pathway of glucuronate interconversion. Crystal structures of Streptococcus mutans KGPDC were determined in the absence and presence of the product analog D-ribulose 5-phosphate. We have observed an 8 A alphaB-helix movement and other structural rearrangements around the active site between the apo-structures and product analog bound structure. These drastic conformational changes upon ligand binding are the first observation of this kind for the KGPDC family. The flexibilities of both the alpha-helix lid and the side chains of Arg144 and Arg197 are associated with substrate binding and product releasing. The open-closed conformational changes of the active site, through the movements of the alpha-helix lid and the arginine residues are important for substrate binding and catalysis.
Organizational Affiliation:
The National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Science, Peking University, Beijing 100871, People's Republic of China.
