2QQU: Crystal Structure Of A Cell-Wall Invertase (D239a) From Arabidopsis Thaliana In Complex With Sucrose

In plants, cell-wall invertases fulfil important roles in carbohydrate partitioning, growth, development and crop yield. In this study, we report on different X-ray crystal structures of Arabidopsis thaliana cell-wall invertase 1 (AtcwINV1) mutants with sucrose. These structures reveal a detailed view of sucrose binding in the active site of the wild-type AtcwINV1. Compared to related enzyme-sucrose complexes, important differences in the orientation of the glucose subunit could be observed. The structure of the E203Q AtcwINV1 mutant showed a complete new binding modus, whereas the D23A, E203A and D239A structures most likely represent the productive binding modus. Together with a hydrophobic zone formed by the conserved W20, W47 and W82, the residues N22, D23, R148, E203, D149 and D239 are necessary to create the ideal sucrose-binding pocket. D239 can interact directly with the glucose moiety of sucrose, whereas K242 has an indirect role in substrate stabilization. Most probably, K242 keeps D239 in a favourable position upon substrate binding. Unravelling the exact position of sucrose in plant cell-wall invertases is a necessary step towards the rational design of superior invertases to further increase crop yield and biomass production.
PDB ID: 2QQUDownload
MMDB ID: 63926
PDB Deposition Date: 2007/7/27
Updated in MMDB: 2011/05
Experimental Method:
x-ray diffraction
Resolution: 2.84  Å
Source Organism:
Similar Structures:
Biological Unit for 2QQU: monomeric; determined by author and by software (PISA)
Molecular Components in 2QQU
Label Count Molecule
Protein (1 molecule)
Beta-fructofuranosidase(Gene symbol: ATBFRUCT1)
Molecule annotation
Chemicals (15 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB