Loading
PDBj
MenuPDBj@FacebookPDBj@X(formerly Twitter)PDBj@BlueSkyPDBj@YouTubewwPDB FoundationwwPDB
RCSB PDBPDBeBMRBAdv. SearchSearch help

2BK6

The X-ray crystal structure of the Listeria innocua H31G Dps mutant.

Summary for 2BK6
Entry DOI10.2210/pdb2bk6/pdb
Related1QGH 2BJY
DescriptorNON-HEME IRON-CONTAINING FERRITIN (2 entities in total)
Functional Keywordsdps (dna binding protein from starved cells), ferroxidase center, mutagenesis study, iron oxidation and storage, metal transport
Biological sourceLISTERIA INNOCUA
Cellular locationCytoplasm : P80725
Total number of polymer chains6
Total formula weight107936.75
Authors
Ilari, A.,Latella, M.C.,Ribacchi, F.,Su, M.,Giangiacomo, L.,Stefanini, S.,Chasteen, N.D.,Chiancone, E. (deposition date: 2005-02-11, release date: 2005-02-14, Last modification date: 2023-12-13)
Primary citationIlari, A.,Latella, M.C.,Ceci, P.,Ribacchi, F.,Su, M.,Giangiacomo, L.,Stefanini, S.,Chasteen, N.D.,Chiancone, E.
The unusual intersubunit ferroxidase center of Listeria innocua Dps is required for hydrogen peroxide detoxification but not for iron uptake. A study with site-specific mutants.
Biochemistry, 44:5579-5587, 2005
Cited by
PubMed Abstract: The role of the ferroxidase center in iron uptake and hydrogen peroxide detoxification was investigated in Listeria innocua Dps by substituting the iron ligands His31, His43, and Asp58 with glycine or alanine residues either individually or in combination. The X-ray crystal structures of the variants reveal only small alterations in the ferroxidase center region compared to the native protein. Quenching of the protein fluorescence was exploited to assess stoichiometry and affinity of metal binding. Substitution of either His31 or His43 decreases Fe(II) affinity significantly with respect to wt L. innocua Dps (K approximately 10(5) vs approximately 10(7) M(-)(1)) but does not alter the binding stoichiometry [12 Fe(II)/dodecamer]. In the H31G-H43G and H31G-H43G-D58A variants, binding of Fe(II) does not take place with measurable affinity. Oxidation of protein-bound Fe(II) increases the binding stoichiometry to 24 Fe(III)/dodecamer. However, the extent of fluorescence quenching upon Fe(III) binding decreases, and the end point near 24 Fe(III)/dodecamer becomes less distinct with increase in the number of mutated residues. In the presence of dioxygen, the mutations have little or no effect on the kinetics of iron uptake and in the formation of micelles inside the protein shell. In contrast, in the presence of hydrogen peroxide, with increase in the number of substitutions the rate of iron oxidation and the capacity to inhibit Fenton chemistry, thereby protecting DNA from oxidative damage, appear increasingly compromised, a further indication of the role of ferroxidation in conferring peroxide tolerance to the bacterium.
PubMed: 15823016
DOI: 10.1021/bi050005e
PDB entries with the same primary citation
Experimental method
X-RAY DIFFRACTION (2.19 Å)
Structure validation

227344

PDB entries from 2024-11-13

PDB statisticsPDBj update infoContact PDBjnumon