2EWT: Crystal Structure Of The Dna-binding Domain Of Bldd

BldD is a central regulator of the developmental process in Streptomyces coelicolor. The 1.8 angstroms resolution structure of the DNA-binding domain of BldD (BldDN) reveals that BldDN forms a compact globular domain composed of four helices (alpha1-alpha4) containing a helix-turn-helix motif (alpha2-alpha3) resembling that of the DNA-binding domain of lambda repressor. The BldDN/DNA complex model led us to design a series of mutants, which revealed the important role of alpha3 and the 'turn' region between alpha2 and alpha3 for DNA recognition. Based on the fact that BldD occupies two operator sites of bldN and whiG and shows significant disparity in the affinity toward the two operator sites when they are disconnected, we propose a model of cooperative binding, which means that the binding of one BldD dimer to the high affinity site facilitates that of the second BldD dimer to the low affinity site. In addition, structural and mutational investigation reveals that the Tyr62Cys mutation, found in the first-identified bldD mutant, can destabilize BldD structure by disrupting the hydrophobic core.
PDB ID: 2EWTDownload
MMDB ID: 39824
PDB Deposition Date: 2005/11/7
Updated in MMDB: 2007/10
Experimental Method:
x-ray diffraction
Resolution: 1.81  Å
Source Organism:
Similar Structures:
Biological Unit for 2EWT: dimeric; determined by author
Molecular Components in 2EWT
Label Count Molecule
Proteins (2 molecules)
Putative DNA-binding Protein(Gene symbol: SCO1489)
Molecule annotation
Chemicals (6 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB