Structural basis for control of integrative and conjugative element excision and transfer by the oligomeric winged helix-turn-helix protein RdfS.

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 individ

SUBMITTER: Verdonk CJ 

PROVIDER: S-EPMC11963761 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature