Structure-function studies of Rgg binding to pheromones and target promoters reveal a model of transcription factor interplay.

ABSTRACT: Regulator gene of glucosyltransferase (Rgg) family proteins, such as Rgg2 and Rgg3, have emerged as primary quorum-sensing regulated transcription factors in Streptococcus species, controlling virulence, antimicrobial resistance, and biofilm formation. Rgg2 and Rgg3 function is regulated by their interaction with oligopeptide quorum-sensing signals called short hydrophobic peptides (SHPs). The molecular basis of Rgg-SHP and Rgg-target DNA promoter specificity was unknown. To close this gap, we determined the cryoelectron microscopy (cryo-EM) structure of Streptococcus thermophilus Rgg3 bound to its quorum-sensing signal, SHP3, and the X-ray crystal structure of Rgg3 alone. Comparison of these structures with that of an Rgg in complex with cyclosporin A (CsA), an inhibitor of

SUBMITTER: Capodagli GC 

PROVIDER: S-EPMC7533842 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature