5KBE

CRYSTAL STRUCTURE OF THE AROMATIC SENSOR DOMAIN OF MOPR IN COMPLEX WITH PHENOL

Summary for 5KBE

• Entry DOI: 10.2210/pdb5kbe/pdb
• Related: 5A1C 5A1D 5A1E 5KBG 5KBH 5KBI
• Descriptor: MopR, ZINC ION, PHENOL, ... (4 entities in total)
• Functional Keywords: transcription, aromatic sensor
• Biological source: Acinetobacter calcoaceticus
• Total number of polymer chains: 2
• Total formula weight: 53093.40

Authors

Ray, S.,Anand, R.,Panjikar, S. (deposition date: 2016-06-03, release date: 2016-07-13, Last modification date: 2024-03-06)

Primary citation

Ray, S.,Gunzburg, M.J.,Wilce, M.,Panjikar, S.,Anand, R.
Structural Basis of Selective Aromatic Pollutant Sensing by the Effector Binding Domain of MopR, an NtrC Family Transcriptional Regulator.
Acs Chem.Biol., 11:2357-2365, 2016

PubMed Abstract: Phenol and its derivatives are common pollutants that are present in industrial discharge and are major xenobiotics that lead to water pollution. To monitor as well as improve water quality, attempts have been made in the past to engineer bacterial in vivo biosensors. However, due to the paucity of structural information, there is insufficiency in gauging the factors that lead to high sensitivity and selectivity, thereby impeding development. Here, we present the crystal structure of the sensor domain of MopR (MopR(AB)) from Acinetobacter calcoaceticus in complex with phenol and its derivatives to a maximum resolution of 2.5 Å. The structure reveals that the N-terminal residues 21-47 possess a unique fold, which are involved in stabilization of the biological dimer, and the central ligand binding domain belongs to the "nitric oxide signaling and golgi transport" fold, commonly present in eukaryotic proteins that bind long-chain fatty acids. In addition, MopR(AB) nests a zinc atom within a novel zinc binding motif, crucial for maintaining structural integrity. We propose that this motif is crucial for orchestrated motions associated with the formation of the effector binding pocket. Our studies reveal that residues W134 and H106 play an important role in ligand binding and are the key selectivity determinants. Furthermore, comparative analysis of MopR with XylR and DmpR sensor domains enabled the design of a MopR binding pocket that is competent in binding DmpR-specific ligands. Collectively, these findings pave way towards development of specific/broad based biosensors, which can act as useful tools for detection of this class of pollutants.

PubMed: 27362503
DOI: 10.1021/acschembio.6b00020

Experimental method

X-RAY DIFFRACTION (2.5 Å)