1IDS

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

1IDS の概要

• エントリーDOI: 10.2210/pdb1ids/pdb
• 分子名称: IRON SUPEROXIDE DISMUTASE, FE (III) ION (3 entities in total)
• 機能のキーワード: superoxide dismutase
• 由来する生物種: Mycobacterium tuberculosis
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 92466.82

構造登録者

Cooper, J.B.,Mcintyre, K.,Wood, S.P.,Zhang, Y.,Young, D. (登録日: 1994-09-29, 公開日: 1994-12-20, 最終更新日: 2024-02-07)

主引用文献

Cooper, J.B.,McIntyre, K.,Badasso, M.O.,Wood, S.P.,Zhang, Y.,Garbe, T.R.,Young, D.
X-ray structure analysis of the iron-dependent superoxide dismutase from Mycobacterium tuberculosis at 2.0 Angstroms resolution reveals novel dimer-dimer interactions.
J.Mol.Biol., 246:531-544, 1995

PubMed Abstract: 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.

PubMed: 7877174
DOI: 10.1006/jmbi.1994.0105

実験手法

X-RAY DIFFRACTION (2 Å)