1B1B

IRON DEPENDENT REGULATOR

Summary for 1B1B

• Entry DOI: 10.2210/pdb1b1b/pdb
• Descriptor: PROTEIN (IRON DEPENDENT REGULATOR), ZINC ION, SULFATE ION, ... (4 entities in total)
• Functional Keywords: ider, iron depedent regulator, mycobacterium tuberculosis, metal binding protein
• Biological source: Mycobacterium tuberculosis
• Total number of polymer chains: 1
• Total formula weight: 16129.10

Authors

Pohl, E.,Holmes, R.K.,Hol, W.G. (deposition date: 1998-11-19, release date: 1999-12-03, Last modification date: 2023-12-27)

Primary citation

Pohl, E.,Holmes, R.K.,Hol, W.G.
Crystal structure of the iron-dependent regulator (IdeR) from Mycobacterium tuberculosis shows both metal binding sites fully occupied.
J.Mol.Biol., 285:1145-1156, 1999

PubMed Abstract: Iron-dependent regulators are a family of metal-activated DNA binding proteins found in several Gram-positive bacteria. These proteins are negative regulators of virulence factors and of proteins of bacterial iron-uptake systems. In this study we present the crystal structure of the iron-dependent regulator (IdeR) from Mycobacterium tuberculosis, the causative agent of tuberculosis. The protein crystallizes in the hexagonal space group P62 with unit cell dimensions a=b=92.6 A, c=63.2 A. The current model comprises the N-terminal DNA-binding domain (residues 1-73) and the dimerization domain (residues 74-140), while the third domain (residues 141-230) is too disordered to be included. The molecule lies on a crystallographic 2-fold axis that generates the functional dimer. The overall structure of the monomer shares many features with the homologous regulator, diphtheria toxin repressor (DtxR) from Corynebacterium diphtheriae. The IdeR structure in complex with Zinc reported here is, however, the first wild-type repressor structure with both metal binding sites fully occupied. This crystal structure reveals that both Met10 and most probably the Sgamma of Cys102 are ligands of the second metal binding site. In addition, there are important changes in the tertiary structure between apo-DtxR and holo-IdeR bringing the putative DNA binding helices closer together in the holo repressor. The mechanism by which metal binding may cause these structural changes between apo and holo wild-type repressor is discussed.

PubMed: 9887269
DOI: 10.1006/jmbi.1998.2339

Experimental method

X-RAY DIFFRACTION (2.6 Å)