PDBsum entry 1gv3

Manganese superoxide dismutase

PDB id: 1gv3

Contents

Protein chains

214 a.a. *

Metals

_MN ×2

Waters ×166

* Residue conservation analysis

PDB id:

1gv3

Name:

Manganese superoxide dismutase

Title:

The 2.0 angstrom resolution structure of the catalytic portion of a cyanobacterial membrane-bound manganese superoxide dismutase

Structure:

Manganese superoxide dismutase. Chain: a, b. Fragment: helical hairpin, alpha/beta domain, residues 30-270. Engineered: yes

Source:

Anabaena sp.. Organism_taxid: 103690. Strain: pcc 7120. Expressed in: escherichia coli. Expression_system_taxid: 469008.

Biol. unit:

Dimer (from PDB file)

Resolution:

2.00Å R-factor: 0.188 R-free: 0.211

Authors:

W.Atzenhofer,G.Regelsberger,U.Jacob,R.Huber,G.A.Peschek,C.Obinger

Key ref:

W.Atzenhofer et al. (2002). The 2.0A resolution structure of the catalytic portion of a cyanobacterial membrane-bound manganese superoxide dismutase. J Mol Biol, 321, 479-489. PubMed id: 12162960 DOI: 10.1016/S0022-2836(02)00624-1

Date:

05-Feb-02 Release date: 08-Aug-02

Protein chains

Q8Z0M1  (Q8Z0M1_NOSS1) -  superoxide dismutase from Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576)

Seq: 270 a.a.

Struc: 214 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.1.15.1.1 - superoxide dismutase.
• Reaction: 2 superoxide + 2 H⁺ = H2O2 + O2
• Cofactor: Fe cation or Mn(2+) or (Zn(2+) and Cu cation)

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

Added reference

DOI no: 10.1016/S0022-2836(02)00624-1

J Mol Biol 321:479-489 (2002)

PubMed id: 12162960

The 2.0A resolution structure of the catalytic portion of a cyanobacterial membrane-bound manganese superoxide dismutase.

W.Atzenhofer, G.Regelsberger, U.Jacob, G.Peschek, P.Furtmüller, R.Huber, C.Obinger.

ABSTRACT

Cyanobacteria are shown to be unique in containing membrane-bound manganese superoxide dismutases (MnSOD). They are homodimeric type 2 membrane proteins that protect this phototrophic organism against oxidative stress. We have determined, for the first time, the 2.0A resolution structure of the catalytic portion of the MnSOD from the filamentous cyanobacterium Anabaena PCC 7120. Within each subunit, both the N-terminal helical hairpin (His94 and His145) and the C-terminal alpha/beta domain (His232 and Asp228) contribute ligands to the catalytic manganese site. Together with a water or hydroxide ion (OH(x)) a five-coordinated trigonal bipyramidal geometry is formed, with OH(x) and His90 forming the axial ligands and manganese shifted out of the equatorial plane in the direction of OH(x). The ligands including OH(x) are tightly constrained by hydrogen bonding with surrounding residues either from the same monomer (Tyr98, Asn144, Trp194, Gln213, Val229, Trp230) or from the neighbouring subunit (Glu231, Tyr235). This underlines the important role of the symmetric dimeric structure of MnSODs in contributing elements to both the active site and the substrate funnel. The Mn cdots, three dots, centered Mn distance (18.4A) is bridged by the hydrogen-bonded His232 of one monomer with Glu231 of the other monomer. A detailed discussion of the structure, a comparison with known structures of soluble MnSODs as well as a model of the cyanobacterial membrane-bound MnSOD is presented.

Selected figure(s)

Figure 6.
Figure 6. Overlay of tube representations of T. thermophilus (blue) and Anabaena PCC 7120 MnSOD dimers (red). The manganese ion is drawn as a yellow sphere. Figure 6, Figure 7 and Figure 8 were produced using MOLSCRIPT. [39 and 40]

Figure 8.
Figure 8. Diagram of the symmetric dimer interface. Residues from each subunit are shown in either orange or yellow. Ribbons are rendered in light blue or brown. Direct interactions between amino acid residues of opposing chains are shown as broken green lines labeled by the corresponding bond length in Å.

The above figures are reprinted by permission from Elsevier: J Mol Biol (2002, 321, 479-489) copyright 2002.

Figures were selected by an automated process.