7F25

Crystal structure of SSB from Salmonella enterica serovar Typhimurium LT2.

This is a non-PDB format compatible entry.

Summary for 7F25

• Entry DOI: 10.2210/pdb7f25/pdb
• Descriptor: Single-stranded DNA-binding protein 1 (2 entities in total)
• Functional Keywords: single-stranded dna-binding protein, ssb, dna binding protein
• Biological source: Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)
• Total number of polymer chains: 2
• Total formula weight: 27525.07

Authors

Luo, R.H.,Huang, Y.H.,Huang, C.Y. (deposition date: 2021-06-10, release date: 2022-05-04, Last modification date: 2023-11-29)

Primary citation

Lin, E.S.,Huang, Y.H.,Luo, R.H.,Basharat, Z.,Huang, C.Y.
Crystal Structure of an SSB Protein from Salmonella enterica and Its Inhibition by Flavanonol Taxifolin.
Int J Mol Sci, 23:-, 2022

PubMed Abstract: Single-stranded DNA (ssDNA)-binding proteins (SSBs) play a central role in cells by participating in DNA metabolism, including replication, repair, recombination, and replication fork restart. SSBs are essential for cell survival and thus an attractive target for potential anti-pathogen chemotherapy. In this study, we determined the crystal structure and examined the size of the ssDNA-binding site of an SSB from serovar Typhimurium LT2 (SeSSB), a ubiquitous opportunistic pathogen which is highly resistant to antibiotics. The crystal structure was solved at a resolution of 2.8 Å (PDB ID 7F25), indicating that the SeSSB monomer possesses an oligonucleotide/oligosaccharide-binding (OB) fold domain at its N-terminus and a flexible tail at its C-terminus. The core of the OB-fold in the SeSSB is made of a six-stranded β-barrel capped by an α-helix. The crystal structure of the SeSSB contained two monomers per asymmetric unit, which may indicate the formation of a dimer. However, the gel-filtration chromatography analysis showed that the SeSSB forms a tetramer in solution. Through an electrophoretic mobility shift analysis, we characterized the stoichiometry of the SeSSB complexed with a series of ssDNA dA homopolymers, and the size of the ssDNA-binding site was determined to be around 22 nt. We also found the flavanonol taxifolin, also known as dihydroquercetin, capable of inhibiting the ssDNA-binding activity of the SeSSB. Thus, this result extended the SSB interactome to include taxifolin, a natural product with a wide range of promising pharmacological activities.

PubMed: 35457218
DOI: 10.3390/ijms23084399

Experimental method

X-RAY DIFFRACTION (2.87 Å)