Naslov
Influence of engineered disulfide bridge on properties of metal sensing transcription factor MntR from Bacillus subtilis

Autori
Leščić Ašler, Ivana ; Jelić Matošević, Zoe ; Radman, Katarina ; Piantanida, Ivo ; Crnolatac, Ivo ; Bertoša, Branimir

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
HDBMB22 From Science to Knowledge : Book of Abstracts / Dulić, Morana ; Sinčić, Nino ; Vrhovac Madunić, Ivana - Zagreb : Hrvatsko društvo za biokemiju i molekularnu biologiju (HDBMB), 2022, 100-100

Skup
Congress of the Croatian Society of Biochemistry and Molecular Biology: From Science to Knowledge (HDBMB22)

Mjesto i datum
Brela, Hrvatska, 28.09.2022. - 01.10.2022

Vrsta sudjelovanja
Poster

Vrsta recenzije
Domaća recenzija

Ključne riječi
Bacillus subtilis ; metallosensor ; MntR protein ; engineered disulfide bridge ; molecular dynamics simulations ; experimental protein characterization

Sažetak
Transition metals are essential for a variety of biological processes in the living cell: they serve as centres of enzyme catalysis, structural constituents of proteins and stabilizers of protein structure. However, they can be toxic if present in high concentrations. Manganese is an essential metal that is used in bacteria for basic cellular processes such as DNA replication and resistance to oxidative stress. Its cytoplasmic concentration and effect on virulence in pathogens varies greatly between species, but it has been identified as necessary for survival and infection in multiple bacteria. The most common mechanism for regulating metal ion homeostasis in bacteria involves metal sensing transcription factors. These proteins reversibly bind metal ions, which modulate their DNA binding affinity. The main goal of our research is to understand details of the molecular mechanism through which bacterial metallosensors accomplish their role in regulating the concentration of manganese ions. We started our investigations with the manganese- responsive metallosensor MntR from B. subtilis. This protein is a homodimer both in its apo- and metal-bound form, and binds two metal ions per monomer which form a binuclear cluster at the dimer interface. Molecular dynamics simulations have shown that even without metal ion present, DNA binding and dimerization domains of the protein come in close contact (that is usually stabilized by Mn2+). To see if we can stabilize this contact differently, we created a double mutant D8C/E99C of B. subtilis MntR with the goal of establishing disulfide bridge that would replace Mn2+ ion in connecting these domains. Both native and mutant protein were overexpressed in E. coli cells and purified via affinity chromatography and size-exclusion chromatography. Their secondary structure properties and DNA binding properties were determined via CD and DSC measurements. Obtained results are discussed, with aim of better understanding of MntR mechanism of action.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Biologija, Interdisciplinarne prirodne znanosti

POVEZANOST RADA