Structure of the manganese-bound manganese transport regulator of Bacillus subtilis
| Autor: | Emmanuel Guedon, Richard G. Brennan, John D. Helmann, Arthur Glasfeld |
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| Rok vydání: | 2003 |
| Předmět: |
Models
Molecular Stereochemistry Structural similarity Metal ions in aqueous solution Molecular Sequence Data Static Electricity Mutant Repressor chemistry.chemical_element Bacillus subtilis Manganese Crystallography X-Ray Metal Bacterial Proteins Structural Biology Catalytic Domain Amino Acid Sequence Molecular Biology Peptide sequence Sequence Homology Amino Acid biology biology.organism_classification Recombinant Proteins Repressor Proteins Crystallography chemistry visual_art Mutagenesis Site-Directed visual_art.visual_art_medium |
| Zdroj: | Nature Structural & Molecular Biology. 10:652-657 |
| ISSN: | 1545-9985 1545-9993 |
| Popis: | The Bacillus subtilis manganese transport regulator, MntR, binds Mn2+ as an effector and is a repressor of transporters that import manganese. A member of the diphtheria toxin repressor (DtxR) family of metalloregulatory proteins, MntR exhibits selectivity for Mn2+ over Fe2+. Replacement of a metal-binding residue, Asp8, with methionine (D8M) relaxes this specificity. We report here the X-ray crystal structures of wild-type MntR and the D8M mutant bound to manganese with 1.75 A and 1.61 A resolution, respectively. The 142-residue MntR homodimer has substantial structural similarity to the 226-residue DtxR but lacks the C-terminal SH3-like domain of DtxR. The metal-binding pockets of MntR and DtxR are substantially different. The cation-to-cation distance between the two manganese ions bound by MntR is 3.3 A, whereas that between the metal ions bound by DtxR is 9 A. D8M binds only a single Mn2+ per monomer, owing to alteration of the metal-binding site. The sole retained metal site adopts pseudo-hexacoordinate geometry rather than the pseudo-heptacoordinate geometry of the MntR metal sites. |
| Databáze: | OpenAIRE |
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