1DHG

HG-SUBSTITUTED DESULFOREDOXIN

Summary for 1DHG

• Entry DOI: 10.2210/pdb1dhg/pdb
• Descriptor: PROTEIN (DESULFOREDOXIN), MERCURY (II) ION (3 entities in total)
• Functional Keywords: rubredoxin type protein, electron transport
• Biological source: Desulfovibrio gigas
• Total number of polymer chains: 2
• Total formula weight: 8015.88

Authors

Archer, M.,Carvalho, A.L.,Teixeira, S.,Moura, I.,Moura, J.J.G.,Rusnak, F.,Romao, M.J. (deposition date: 1999-03-22, release date: 1999-07-09, Last modification date: 2023-08-09)

Primary citation

Archer, M.,Carvalho, A.L.,Teixeira, S.,Moura, I.,Moura, J.J.,Rusnak, F.,Romao, M.J.
Structural studies by X-ray diffraction on metal substituted desulforedoxin, a rubredoxin-type protein.
Protein Sci., 8:1536-1545, 1999

PubMed Abstract: Desulforedoxin (Dx), isolated from the sulfate reducing bacterium Desulfovibrio gigas, is a small homodimeric (2 x 36 amino acids) protein. Each subunit contains a high-spin iron atom tetrahedrally bound to four cysteinyl sulfur atoms, a metal center similar to that found in rubredoxin (Rd) type proteins. The simplicity of the active center in Dx and the possibility of replacing the iron by other metals make this protein an attractive case for the crystallographic analysis of metal-substituted derivatives. This study extends the relevance of Dx to the bioinorganic chemistry field and is important to obtain model compounds that can mimic the four sulfur coordination of metals in biology. Metal replacement experiments were carried out by reconstituting the apoprotein with In3+, Ga3+, Cd2+, Hg2+, and Ni2+ salts. The In3+ and Ga3+ derivatives are isomorphous with the iron native protein; whereas Cd2+, Hg2+, and Ni2+ substituted Dx crystallized under different experimental conditions, yielding two additional crystal morphologies; their structures were determined by the molecular replacement method. A comparison of the three-dimensional structures for all metal derivatives shows that the overall secondary and tertiary structures are maintained, while some differences in metal coordination geometry occur, namely, bond lengths and angles of the metal with the sulfur ligands. These data are discussed in terms of the entatic state theory.

PubMed: 10422844

Experimental method

X-RAY DIFFRACTION (2.5 Å)