1UHE: Crystal Structure Of Aspartate Decarboxylase, Isoaspargine Complex

l-Aspartate alpha-decarboxylase (ADC), encoded by the panD gene, catalyzes the conversion of l-aspartate into beta-alanine. In the microorganisms, beta-alanine is required for the synthesis of pantothenate (vitamin B(5)), which is the precursor of 4'-phosphopantetheine and coenzyme A. We have determined the crystal structure of Helicobacter pylori ADC, a tetrameric enzyme, in two forms: the apo structure at 2.0 A resolution and the isoasparagine complex structure at 1.55 A resolution. All subunits of the tetramer are self-processed at the Gly24-Ser25 linkage, producing the smaller beta chain (residues 1-24) and the larger alpha chain (residues 25-117). Each subunit contains nine beta-strands and three alpha-helices; it is folded into the double-psi beta-barrel structure. In the apo structure, the new amino terminus of the alpha chain, Ser25, is converted into a pyruvoyl group. In the isoasparagine complex structure, the substrate analog is covalently attached to the pyruvoyl group. This structure represents the enzyme-substrate Schiff base intermediate that was proposed to form prior to the decarboxylation step in the catalytic cycle of ADC. Thus our study provides direct structural evidence for the reaction mechanism of ADC.
PDB ID: 1UHEDownload
MMDB ID: 28755
PDB Deposition Date: 2003/7/1
Updated in MMDB: 2012/11
Experimental Method:
x-ray diffraction
Resolution: 1.55  Å
Source Organism:
Similar Structures:
Biological Unit for 1UHE: octameric; determined by author and by software (PISA)
Molecular Components in 1UHE
Label Count Molecule
Proteins (8 molecules)
Aspartate 1-decarboxylase Beta Chain(Gene symbol: HP0034)
Molecule annotation
Aspartate 1-decarboxylase Alpha Chain(Gene symbol: HP0034)
Molecule annotation
Chemicals (4 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB