3TGN: Crystal Structure Of The Zinc-Dependent Marr Family Transcriptional Regulator Adcr In The Zn(Ii)-Bound State

Streptococcus pneumoniae adhesin competence regulator (AdcR), the first metal-dependent member of the multiple antibiotic resistance regulator (MarR) family of proteins, represses the transcription of a high-affinity zinc-specific uptake transporter, a group of surface antigen zinc-binding pneumococcal histidine triad proteins (PhtA, PhtB, PhtD, and PhtE), and an AdcA homologue (AdcAII). The 2.0 A resolution structure of Zn(II)-bound AdcR reveals a highly helical two-fold-symmetric dimer with two distinct metal-binding sites per protomer. Zn(II) is tetrahedrally coordinated by E24, H42, H108, and H112 in what defines the primary sensing site in AdcR. Site 2 is a tetracoordinate site whose function is currently unknown. NMR methyl group perturbation experiments reveal that Zn(II) drives a global change in the structure of apo-AdcR that stabilizes a conformation that is compatible with DNA binding. This co-repression mechanism is unprecedented in MarR transcriptional regulators.
PDB ID: 3TGNDownload
MMDB ID: 95387
PDB Deposition Date: 2011/8/17
Updated in MMDB: 2011/12
Experimental Method:
x-ray diffraction
Resolution: 2  Å
Source Organism:
Similar Structures:
Biological Unit for 3TGN: dimeric; determined by author and by software (PISA)
Molecular Components in 3TGN
Label Count Molecule
Proteins (2 molecules)
ADC Operon Repressor Adcr
Molecule annotation
Chemicals (4 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB