3SXP image
Deposition Date 2011-07-15
Release Date 2012-02-08
Last Version Date 2023-09-13
Entry Detail
PDB ID:
3SXP
Keywords:
Title:
Crystal Structure of Helicobacter pylori ADP-L-glycero-D-manno-heptose-6-epimerase (rfaD, HP0859)
Biological Source:
Source Organism:
Host Organism:
Method Details:
Experimental Method:
Resolution:
2.55 Å
R-Value Free:
0.27
R-Value Work:
0.23
R-Value Observed:
0.23
Space Group:
I 1 2 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:ADP-L-glycero-D-mannoheptose-6-epimerase
Gene (Uniprot):HPG27_813
Mutations:G7E
Chain IDs:A, B, C, D, E
Chain Length:362
Number of Molecules:5
Biological Source:Helicobacter pylori
Ligand Molecules
Primary Citation
The crystal structure of ADP-L-glycero-D-manno-heptose-6-epimerase (HP0859) from Helicobacter pylori.
Biochim.Biophys.Acta 1814 1641 1647 (2011)
PMID: 21979583 DOI: 10.1016/j.bbapap.2011.09.006

Abstact

Helicobacter pylori, the human pathogen that affects about half of the world population and that is responsible for gastritis, gastric ulcer and adenocarcinoma and MALT lymphoma, owes much of the integrity of its outer membrane on lipopolysaccharides (LPSs). Together with their essential structural role, LPSs contribute to the bacterial adherence properties, as well as they are well characterized for the capability to modulate the immuno-response. In H. pylori the core oligosaccharide, one of the three main domains of LPSs, shows a peculiar structure in the branching organization of the repeating units, which displayed further variability when different strains have been compared. We present here the crystal structure of ADP-L-glycero-D-manno-heptose-6-epimerase (HP0859, rfaD), the last enzyme in the pathway that produces L-glycero-D-manno-heptose starting from sedoheptulose-7-phosphate, a crucial compound in the synthesis of the core oligosaccharide. In a recent study, a HP0859 knockout mutant has been characterized, demonstrating a severe loss of lipopolysaccharide structure and a significant reduction of adhesion levels in an infection model to AGS cells, if compared with the wild type strain, in good agreement with its enzymatic role. The crystal structure reveals that the enzyme is a homo-pentamer, and NAD is bound as a cofactor in a highly conserved pocket. The substrate-binding site of the enzyme is very similar to that of its orthologue in Escherichia coli, suggesting also a similar catalytic mechanism.

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Primary Citation of related structures