1ids

X-RAY STRUCTURE ANALYSIS OF THE IRON-DEPENDENT SUPEROXIDE DISMUTASE FROM MYCOBACTERIUM TUBERCULOSIS AT 2.0 ANGSTROMS RESOLUTIONS REVEALS NOVEL DIMER-DIMER INTERACTIONS

spinqualitylabelsall models 1ids, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1ids is a 4 chain structure with sequence from Mycobacterium tuberculosis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: FE Activity: Superoxide dismutase, with EC number 1.15.1.1 Resources: FirstGlance, OCA, RCSB, PDBsum Function [SODF_MYCTU] Destroys superoxide anion radicals which are normally produced within the cells and which are toxic to biological systems. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed The X-ray structure of the tetrameric iron-dependent superoxide dismutase from Mycobacterium tuberculosis has been refined to an R-factor of 0.167 and a correlation coefficient of 0.954 at 2.0 A resolution. The crystals are monoclinic P2(1) and have four subunits related by strong non-crystallographic 222 (or D2) symmetry in the asymmetric unit. 198 of the 207 amino acids of each subunit are defined by the electron density which shows that they adopt the conserved fold of other iron- or manganese-dependent SODs. The structure can be divided into two domains, the N-terminal domain involving an extended region followed by two projecting antiparallel alpha-helices, and the C-terminal domain containing four more helical segments with a three-stranded antiparallel beta-sheet inserted sequentially between the fourth and fifth helices. The catalytic iron is co-ordinated by five ligands: three histidines (residues 28, 76 and 164), one aspartate (160) and a solvent molecule. The inferred positions of protons at the active site are consistent with the solvent ligand being a hydroxide ion. This ligand interacts with His145 in the Mycobacterium tuberculosis SOD. In the highly homologous Mycobacterium leprae Mn-SOD, the histidine is replaced by glutamine, this being the only significant residue difference within 10 A of the Fe3+. The nature of the amino acid at this position may influence the metal ion specificity of these enzymes. The subunits of the Mycobacterium tuberculosis SOD associate by polar contacts to form dimers, which closely resemble those of other dimeric or tetrameric Fe- or Mn-SODs. However, the dimer-dimer interactions within the tetramer are novel, being dominated by dimerisation of the 144 to 152 loop regions which connect the outer two beta-strands of the three-membered beta-sheet. This contrasts strongly with the other tetrameric Fe- or Mn-SODs where the dimer-dimer association is dominated by the projecting alpha alpha-turn in the N-terminal domain. X-ray structure analysis of the iron-dependent superoxide dismutase from Mycobacterium tuberculosis at 2.0 Angstroms resolution reveals novel dimer-dimer interactions.,Cooper JB, McIntyre K, Badasso MO, Wood SP, Zhang Y, Garbe TR, Young D J Mol Biol. 1995 Mar 3;246(4):531-44. PMID:7877174 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Superoxide Dismutase

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