In HspA from Helicobacter pylori vicinal disulfide bridges are a key determinant of domain B structure.
Helicobacter pylori produces a heat shock protein A (HspA) that is unique to this bacteria. While the first 91 residues (domain A) of the protein are similar to GroES, the last 26 (domain B) are unique to HspA. Domain B contains eight histidines and four cysteines and was suggested to bind nickel. We have produced HspA and two mutants: Cys94Ala and Cys94Ala/Cys111Ala and identified the disulfide bridge pattern of the protein. We found that the cysteines are engaged in three disulfide bonds: Cys51/Cys53, Cys94/Cys111 and Cys95/Cys112 that result in a unique closed loop structure for the domain B.
Loguercio
Salvatore
S
Department of Biological Sciences and CNISM, University of Naples "Federico II", Via Mezzocannone 16, I-80134 Naples, Italy.
Dian
Cyril
C
Flagiello
Angela
A
Scannella
Alessandra
A
Pucci
Piero
P
Terradot
Laurent
L
Zagari
Adriana
A
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D003545:Cysteine / Q000737:chemistry* / Q000235:genetics; D006360:Heat-Shock Proteins / Q000737:chemistry* / Q000235:genetics; D016480:Helicobacter pylori / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D017434:Protein Structure, Tertiary
D001426:Bacterial Proteins; D006360:Heat-Shock Proteins; C113725:HspA protein, bacteria; D003545:Cysteine