Streptococcus pneumoniae adhesin competence regulator (AdcR), the first metal-dependent member of the multiple antibiotic resistance regulator (MarR) family of proteins, represses the transcription of a high-affinity zinc-specific uptake transporter, a group of surface antigen zinc-binding pneumococcal histidine triad proteins (PhtA, PhtB, PhtD, and PhtE), and an AdcA homologue (AdcAII). The 2.0 Å resolution structure of Zn(II)-bound AdcR reveals a highly helical two-fold-symmetric dimer with two distinct metal-binding sites per protomer. Zn(II) is tetrahedrally coordinated by E24, H42, H108, and H112 in what defines the primary sensing site in AdcR. Site 2 is a tetracoordinate site whose function is currently unknown. NMR methyl group perturbation experiments reveal that Zn(II) drives a global change in the structure of apo-AdcR that stabilizes a conformation that is compatible with DNA binding. This co-repression mechanism is unprecedented in MarR transcriptional regulators.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3246308 | PMC |
http://dx.doi.org/10.1021/ja2080532 | DOI Listing |
Int J Biol Macromol
January 2025
Department of Applied Biology, School of Biotechnology, East China University of Science and Technology, Shanghai 200237, China.
Lincomycin, produced by the actinomycete Streptomyces lincolnensis, is highly effective against Gram-positive bacteria and protozoans, making it widely used in clinical settings. This study identified LcbR2, a MarR family transcriptional regulator, as an activator of lincomycin biosynthesis. Knocking out the lcbR2 gene reduced lincomycin production by 63.
View Article and Find Full Text PDFAppl Environ Microbiol
January 2025
Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil.
Unlabelled: is a ubiquitous environmental pathogen. Despite its remarkable adaptability, little is known about the mechanisms of stress resistance in this bacterium. Here, in a screen for iron-susceptible transposon mutants, we identified a cytochrome that protects against multiple stresses.
View Article and Find Full Text PDFAm J Epidemiol
January 2025
The Suzanne Dworak-Peck School of Social Work at the University of Southern California, Los Angeles, CA.
Intimate partner violence (IPV) and homelessness can have devastating health consequences for pregnant women. Using the Pregnancy Risk Assessment Monitoring System, we assessed differences in the association of physical IPV before and/or during pregnancy with adverse health outcomes between women experiencing homelessness (WEH) and domiciled women. Among 186,891 respondents, representing an estimated 11,489,161 women, 27.
View Article and Find Full Text PDFJ Natl Compr Canc Netw
November 2024
36National Comprehensive Cancer Network.
The NCCN Guidelines for the Management of Immunotherapy-Related Toxicities are intended to provide oncology practitioners with guidance on how to manage the wide-ranging and potentially fatal toxicities that may occur with cancer immunotherapy. The guidelines address immune-related adverse events related to immune checkpoint inhibitors, CAR T-cell therapies, and lymphocyte engagers (which include T-cell-engaging bispecific antibodies). These NCCN Guidelines Insights highlight recent guideline updates pertaining to the management of emerging toxicities related to cancer immunotherapy.
View Article and Find Full Text PDFmBio
December 2024
Université Côte d'Azur, INRAE, CNRS, ISA, Sophia-Antipolis, France.
Rhizobia associate with legumes and induce the formation of nitrogen-fixing nodules. The regulation of bacterial redox state plays a major role in symbiosis, and reactive oxygen species produced by the plant are known to activate signaling pathways. However, only a few redox-sensing transcriptional regulators (TRs) have been characterized in the microsymbiont.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!