3EXT
Crystal structure of KGPDC from Streptococcus mutans
Summary for 3EXT
| Entry DOI | 10.2210/pdb3ext/pdb |
| Related | 3EXR 3EXS |
| Descriptor | RmpD (Hexulose-6-phosphate synthase), MAGNESIUM ION (3 entities in total) |
| Functional Keywords | beta barrel, lyase |
| Biological source | Streptococcus mutans |
| Total number of polymer chains | 1 |
| Total formula weight | 23874.53 |
| Authors | |
| Primary citation | Li, G.L.,Liu, X.,Nan, J.,Brostromer, E.,Li, L.F.,Su, X.D. Open-closed conformational change revealed by the crystal structures of 3-keto-L-gulonate 6-phosphate decarboxylase from Streptococcus mutans Biochem.Biophys.Res.Commun., 381:429-433, 2009 Cited by 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. PubMed: 19222992DOI: 10.1016/j.bbrc.2009.02.049 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2 Å) |
Structure validation
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