9CHN

P. vulgaris trimeric HigBA- operator 2 DNA

Summary for 9CHN

• Entry DOI: 10.2210/pdb9chn/pdb
• Descriptor: Antitoxin HigA, Endoribonuclease HigB, DNA (5'-D(*GP*TP*AP*TP*TP*AP*CP*AP*CP*AP*CP*CP*AP*TP*GP*TP*AP*AP*TP*AP*C)-3'), ... (6 entities in total)
• Functional Keywords: toxin, antitoxin, promoter, dna binding protein, antitoxin-dna binding protein-dna complex, antitoxin/dna binding protein/dna
• Biological source: Proteus vulgaris; More
• Total number of polymer chains: 5
• Total formula weight: 47163.36

Authors

Pavelich, I.J.,Schureck, M.A.,Hoffer, E.D.,Dunham, C.M. (deposition date: 2024-07-01, release date: 2025-07-02, Last modification date: 2026-01-14)

Primary citation

Pavelich, I.J.,Schureck, M.A.,Srinivas, P.,Blackburn, T.M.,Wang, D.,Hoffer, E.D.,Boamah, M.,Zaldana, K.,Onuoha, N.,Miles, S.J.,Grabowicz, M.,Okafor, C.D.,Dunham, C.M.
Antitoxin control of optimal transcriptional repression in the atypical HigB-HigA toxin-antitoxin system from Proteus vulgaris.
Nucleic Acids Res., 53:-, 2025

PubMed Abstract: Bacterial toxin-antitoxin (TA) pairs transcriptionally autoregulate their expression via a repression/derepression mechanism in response to changing environmental conditions. The structural diversity of TA systems influences the mechanisms of transcriptional regulation. Here, we define the molecular mechanism for the plasmid-encoded HigB-HigA TA pair originally identified in a post-operative infection with antibiotic-resistant Proteus vulgaris. We determine DNA binding and promoter activity by the HigB-HigA complex supported by structural biology and molecular dynamics simulations of an elusive DNA operator-TA repressor complex. To define the optimal oligomeric TA repressor-DNA operator complex required for derepression, we engineered a dedicated trimeric HigB-HigA2 complex that represses transcription more than 26-fold as compared to the tetrameric HigB2-HigA2. These results expand the known diversity of how the HigB-HigA TA family is autoregulated.

PubMed: 40671524
DOI: 10.1093/nar/gkaf610

Experimental method

X-RAY DIFFRACTION (2.8 Å)