Files and links (1)
CC BY V4.0, Open Access
Journal article
Structural basis for control of integrative and conjugative element excision and transfer by the oligomeric winged helix–turn–helix protein RdfS
Nucleic Acids Research, Vol.53(6), gkaf249
2025
Abstract
Winged helix–turn–helix (wHTH) proteins are diverse DNA-binding proteins that often oligomerize on DNA and participate in DNA recombination and transcriptional regulation. wHTH recombination directionality factors (RDFs) associated with tyrosine recombinases, stimulate excision of prophage and integrative and conjugative elements (ICEs). RdfS is required for excision and conjugation of the Mesorhizobium japonicum R7A ICE, ICEMlSymR7A, which carries genes for nitrogen-fixing symbiosis. We show RdfS binds to DNA regions within the IntS attachment site (attP) and within the rdfS promoter, enabling RdfS to coordinate rdfS/intS expression and stimulate RdfS/IntS-mediated ICEMlSymR7A excision. Several RdfS DNA-binding sites were identified. However, no consensus motif was apparent and no individual nucleotide substitutions in attP prevented RdfS binding. RdfS forms extensive helical filaments in crystals, with subunits contacting via a novel α1-helix absent in other wHTH-RDFs. RdfS oligomerized in solution in the absence of DNA. Molecular dynamics simulations supported a role for the α1-helix in oligomerization and compaction of nucleoprotein complexes. Removal of RdfS-α1 did not eliminate DNA-binding in vitro but reduced oligomerization and abolished RdfS-mediated ICEMlSymR7A excision and conjugative transfer. We propose the novel RdfS-α1 mediated oligomerization enables RdfS to specifically recognize larger DNA regions with low primary sequence conservation through an indirect readout mechanism.
Details
- Title
- Structural basis for control of integrative and conjugative element excision and transfer by the oligomeric winged helix–turn–helix protein RdfS
- Authors/Creators
- C.J. VerdonkM. Agostino - Curtin UniversityKarina Yui Eto - Curtin UniversityDrew Hall - Murdoch UniversityCharles S. Bond - The University of Western AustraliaJoshua P. Ramsay - Curtin University
- Publication Details
- Nucleic Acids Research, Vol.53(6), gkaf249
- Publisher
- Oxford University Press on behalf of Nucleic Acids Research.
- Number of pages
- 15
- Grant note
- Australian Research Council Future Fellowship - Australian Government: FT170100235 Australian Government Research Training Program (RTP) ScholarshipCurtin Medical School, Curtin University
J.P.R. is the recipient of an Australian Research Council Future Fellowship (Project ID FT170100235) funded by the Australian Government. C.J.V. is the recipient of an Australian Government Research Training Program (RTP) Scholarship administered by the University of Western Australia. C.J.V. and J.P.R. received funding from Curtin Medical School, Curtin University.
- Identifiers
- 991005757633607891
- Copyright
- © The Author(s) 2025.
- Murdoch Affiliation
- Australian National Phenome Centre
- Resource Type
- Journal article
UN Sustainable Development Goals (SDGs)
This output has contributed to the advancement of the following goals:
Source: InCites
Metrics
2 File views/ downloads
9 Record Views
InCites Highlights
These are selected metrics from InCites Benchmarking & Analytics tool, related to this output
- Collaboration types
- Domestic collaboration
- Citation topics
- 3 Agriculture, Environment & Ecology
- 3.97 Plant Pathology
- 3.97.892 Rhizobium-Legume Symbiosis
- Web Of Science research areas
- Biochemistry & Molecular Biology
- ESI research areas
- Biology & Biochemistry