The crystal structure of the superoxide dismutase from Helicobacter pylori reveals a structured C-terminal extension.
Superoxide dismutases (SODs) are key enzymes for fighting oxidative stress. Helicobacter pylori produces a single SOD (HpSOD) which contains iron. The structure of this antioxidant protein has been determined at 2.4 A resolution. It is a dimer of two identical subunits with one iron ion per monomer. The protein shares 53% sequence identity with the corresponding enzyme from Escherichia coli. The model is compared with those of other dimeric Fe-containing SODs. HpSOD shows significant differences in relation to other SODs, the most important being an extended C-terminal tail. This structure provides a model for closely related sequences from species such as Campylobacter, where no structures are currently known. The structure of extended carboxyl termini is discussed in light of putative functions it may serve.
Esposito
Luciana
L
Institute of Biostructures and Bioimaging, CNR, Via Mezzocannone 16, I-80134, Naples, Italy. luciana.esposito@unina.it
Seydel
Anke
A
Aiello
Rosa
R
Sorrentino
Giosué
G
Cendron
Laura
L
Zanotti
Giuseppe
G
Zagari
Adriana
A
D000595:Amino Acid Sequence; D001665:Binding Sites; D018360:Crystallography, X-Ray; D019281:Dimerization; D016480:Helicobacter pylori / Q000737:chemistry / Q000201:enzymology*; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017510:Protein Folding; D054730:Protein Interaction Domains and Motifs; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D013482:Superoxide Dismutase / Q000737:chemistry* / Q000378:metabolism
D013482:Superoxide Dismutase