6FI9

Crystal Structure of a zinc-responsive MarR family member, Lactococcus lactis ZitR

Summary for 6FI9

• Entry DOI: 10.2210/pdb6fi9/pdb
• Descriptor: Transcriptional regulator ZitR, ZINC ION (2 entities in total)
• Functional Keywords: zinc transport regulator, adhesin competence regulator, multiple antibiotic resistance regulator, zinc responsive repressor, winged helix-turn-helix dna binding domain, gene regulation
• Biological source: Lactococcus lactis subsp. cremoris (strain MG1363)
• Total number of polymer chains: 8
• Total formula weight: 131507.09

Authors

Varela, P.F.,Legrand, P. (deposition date: 2018-01-17, release date: 2019-02-20, Last modification date: 2024-05-08)

Primary citation

Varela, P.F.,Velours, C.,Aumont-Nicaise, M.,Pineau, B.,Legrand, P.,Poquet, I.
Biophysical and structural characterization of a zinc-responsive repressor of the MarR superfamily.
PLoS ONE, 14:e0210123-e0210123, 2019

PubMed Abstract: The uptake of zinc, which is vital in trace amounts, is tightly controlled in bacteria. For this control, bacteria of the Streptococcaceae group use a Zn(II)-binding repressor named ZitR in lactococci and AdcR in streptococci, while other bacteria use a Zur protein of the Ferric uptake regulator (Fur) superfamily. ZitR and AdcR proteins, characterized by a winged helix-turn-helix DNA-binding domain, belong to the multiple antibiotic resistance (MarR) superfamily, where they form a specific group of metallo-regulators. Here, one such Zn(II)-responsive repressor, ZitR of Lactococcus lactis subspecies cremoris strain MG1363, is characterized. Size Exclusion Chromatography-coupled to Multi Angle Light Scattering, Circular Dichroism and Isothermal Titration Calorimetry show that purified ZitR is a stable dimer complexed to Zn(II), which is able to bind its two palindromic operator sites on DNA fragments. The crystal structure of ZitR holo-form (Zn(II)4-ZitR2), has been determined at 2.8 Å resolution. ZitR is the fourth member of the MarR metallo-regulator subgroup whose structure has been determined. The folding of ZitR/AdcR metallo-proteins is highly conserved between both subspecies (cremoris or lactis) in the Lactococcus lactis species and between species (Lactococcus lactis and Streptococcus pneumoniae or pyogenes) in the Streptococcaceae group. It is also similar to the folding of other MarR members, especially in the DNA-binding domain. Our study contributes to better understand the biochemical and structural properties of metallo-regulators in the MarR superfamily.

PubMed: 30753183
DOI: 10.1371/journal.pone.0210123

Experimental method

X-RAY DIFFRACTION (2.8 Å)