Multicopy plasmids carrying the sopB gene of the F plasmid inhibit stable inheritance of a coexisting mini-F plasmid. This incompatibility, termed IncG, is found to be caused by excess amounts of the SopB protein, which is essential for accurate partitioning of plasmid DNA molecules into daughter cells. A sopB-carrying multicopy plasmid that shows the IncG+ phenotype was mutagenized in vitro and IncG negative mutant plasmids were isolated. Among these amber and missense mutants of sopB, mutants with a low plasmid copy number and a mutant in the Shine-Dalgarno sequence for translation of the SopB protein were obtained. These results demonstrate that the IncG phenotype is caused by the SopB protein, and that the incompatibility is expressed only when the protein is overproduced. This suggests that the protein must be kept at appropriate concentrations to ensure stable maintenance of the plasmid.

Download full-text PDF

Source
http://dx.doi.org/10.1007/BF00328125DOI Listing

Publication Analysis

Top Keywords

sopb protein
12
partitioning plasmid
8
plasmid
7
protein
6
sopb
5
plasmid overproduction
4
overproduction essential
4
essential protein
4
protein partition
4
partition inhibits
4

Similar Publications

Ginsenoside Ro improves Salmonella Typhimurium-induced colitis through inhibition of the virulence factors SopB and SopE2 via the RAC1/CDC42/ARP2/3 pathway.

FASEB J

December 2024

State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine Jilin University, Center of Infectious Diseases and Pathogen Biology, Department of Infectious Diseases, First Hospital of Jilin University, Changchun, China.

Salmonella enterica serovar Typhimurium (S. Typhimurium) poses a serious threat to human and animal health, and there is an urgent need to develop new therapeutic agents. In our in vivo study, ginsenoside Ro (Ro) reduced the mortality rate of S.

View Article and Find Full Text PDF
Article Synopsis
  • Arboviruses, transmitted by arthropods, are a significant public health threat, prompting research into host factors that inhibit their infection for prevention and treatment strategies.* -
  • A study screened 210 effector proteins from bacteria in bat and human cells, identifying three effectors (IpaH4, SopB, SidM) that boost arbovirus replication and highlighting the specific roles of various effectors.* -
  • The research particularly focused on IpaH4's mechanism, revealing that it targets RNF214, an antiviral protein, for degradation, suggesting that RNF214 is crucial for innate immunity against arboviruses.*
View Article and Find Full Text PDF
Article Synopsis
  • - Diarrhea in lambs, a critical health issue in ovine medicine, leads to substantial economic losses due to high mortality rates and treatment costs, with Salmonella and enterotoxigenic E. coli as primary causes.
  • - The study aimed to analyze genetic variations, gene expression, and biomarkers related to inflammation and oxidative stress in lambs with diarrhea, alongside identifying different strains of the pathogens involved.
  • - Results indicated the presence of specific virulence genes associated with E. coli and Salmonella in all diarrheic lambs, as well as identified genetic markers related to immune response, antioxidant activity, and gastrointestinal health.
View Article and Find Full Text PDF

Enteric pathogens engage in complex interactions with the host and the resident microbiota to establish gut colonization. Although mechanistic interactions between enteric pathogens and bacterial commensals have been extensively studied, whether and how commensal fungi affect pathogenesis of enteric infections remains largely unknown. Here we show that colonization with the common human gut commensal fungus worsened infections with the enteric pathogen serovar Typhimurium.

View Article and Find Full Text PDF

Green synthesis methods offer a cost-effective and environmentally friendly approach to producing nanoparticles (NPs), particularly metal-based oxides. This study explores the green synthesis of copper oxide nanoparticles using ( Miller) leaf extract. The characterization revealed a unique sago-shaped morphology revealed by field-emission scanning electron microscopy and X-ray diffraction analysis.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!