TY - JOUR
T1 - The first crystal structure of class III superoxide reductase from Treponema pallidum
AU - Santos-Silva, Teresa
AU - Trincão, José
AU - Carvalho, Ana Luísa
AU - Bonifácio, Cecília
AU - Auchère, Françoise
AU - Raleiras, Patrícia
AU - Moura, Isabel
AU - Moura, José J. G.
AU - Romão, Maria João
N1 - This work was supported in part by Fundac¸ ão para a Ciência e Tecnologia, SFRH/BD/6358/2001 (T.S.-S.), BPD-9444/2002 (J.T.) and COST D21 – WG6 (I.M., J.J.G.M. and M.J.R.). The authors would like to thank Mário Sadio for his help in the preparation of Fig. 1, Hassan Berhali, from beamline BM14, for his help during synchrotron data collection at the ESRF, Grenoble, France, and the EMBL EU-HCMP programme for supporting travel and accommodation expenses. The authors would also like to thank the Analytical services of laboratory of REQUIMTE for the ICP-OES results.
PY - 2006/7/1
Y1 - 2006/7/1
N2 - Superoxide reductase (SOR) is a metalloprotein containing a non-heme iron centre, responsible for the scavenging of superoxide radicals in the cell. The crystal structure of Treponema pallidum (Tp) SOR was determined using soft X-rays and synchrotron radiation. Crystals of the oxidized form were obtained using poly(ethylene glycol) and MgCl2 and diffracted beyond 1.55 Å resolution. The overall architecture is very similar to that of other known SORs but TpSOR contains an N-terminal domain in which the desulforedoxin-type Fe centre, found in other SORs, is absent. This domain conserves the β-barrel topology with an overall arrangement very similar to that of other SOR proteins where the centre is present. The absence of the iron ion and its ligands, however, causes a decrease in the cohesion of the domain and some disorder is observed, particularly in the region where the metal would be harboured. The C-terminal domain exhibits the characteristic immunoglobulin-like fold and harbours the Fe(His)4(Cys) active site. The five ligands of the iron centre are well conserved despite some disorder observed for one of the four molecules in the asymmetric unit. The participation of a glutamate as the sixth ligand of some of the iron centres in Pyrococcus furiosus SOR was not observed in TpSOR. A possible explanation is that either X-ray photoreduction occurred or there was a mixture of redox states at the start of data collection. In agreement with earlier proposals, details in the TpSOR structure also suggest that Lys49 might be involved in attraction of superoxide to the active site.
AB - Superoxide reductase (SOR) is a metalloprotein containing a non-heme iron centre, responsible for the scavenging of superoxide radicals in the cell. The crystal structure of Treponema pallidum (Tp) SOR was determined using soft X-rays and synchrotron radiation. Crystals of the oxidized form were obtained using poly(ethylene glycol) and MgCl2 and diffracted beyond 1.55 Å resolution. The overall architecture is very similar to that of other known SORs but TpSOR contains an N-terminal domain in which the desulforedoxin-type Fe centre, found in other SORs, is absent. This domain conserves the β-barrel topology with an overall arrangement very similar to that of other SOR proteins where the centre is present. The absence of the iron ion and its ligands, however, causes a decrease in the cohesion of the domain and some disorder is observed, particularly in the region where the metal would be harboured. The C-terminal domain exhibits the characteristic immunoglobulin-like fold and harbours the Fe(His)4(Cys) active site. The five ligands of the iron centre are well conserved despite some disorder observed for one of the four molecules in the asymmetric unit. The participation of a glutamate as the sixth ligand of some of the iron centres in Pyrococcus furiosus SOR was not observed in TpSOR. A possible explanation is that either X-ray photoreduction occurred or there was a mixture of redox states at the start of data collection. In agreement with earlier proposals, details in the TpSOR structure also suggest that Lys49 might be involved in attraction of superoxide to the active site.
KW - Iron-protein
KW - Oxidative stress
KW - Superoxide reductase
KW - Syphilis
KW - Treponema pallidum
UR - http://www.scopus.com/inward/record.url?scp=33745364810&partnerID=8YFLogxK
U2 - 10.1007/s00775-006-0104-y
DO - 10.1007/s00775-006-0104-y
M3 - Article
C2 - 16791639
AN - SCOPUS:33745364810
SN - 0949-8257
VL - 11
SP - 548
EP - 558
JO - JBIC Journal of Biological Inorganic Chemistry
JF - JBIC Journal of Biological Inorganic Chemistry
IS - 5
ER -