The Escherichia coli protein Hha is a temperature- and osmolarity-dependent modulator of the expression of the hemolysin operon. The Hha protein was purified and its DNA-binding properties analyzed. Hha binds in a non-specific manner throughout the upstream regulatory region of the hemolysin operon in the recombinant hemolytic plasmid pANN202-312. A search for interacting proteins revealed that Hha interacts with H-NS. DNA-binding studies showed that, in vitro, Hha and H-NS together form a complex with DNA that differs from those formed with either protein alone. These data, together with the effects of hha and hns mutations on the expression of the hemolysin genes, suggest that in vivo H-NS and Hha form a nucleoid-protein complex that accounts for the thermo-osmotic regulation of the hemolysin operon in E. coli.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1007/s004380051178 | DOI Listing |
Genes Genomics
October 2024
Collaborative Innovation Center of Marine Science and Technology, Hainan Provincial Key Laboratory for Tropical Hydrobiology and Biotechnology, School of Marine Biology and Fisheries, Hainan University, Haikou, 570228, P.R. China.
Virulence
December 2024
Department of Clinical Laboratory, Shanghai Pulmonary Hospital, School of Medicine, Tongji University, Shanghai, People's Republic of China.
The ability to form robust biofilms and secrete a diverse array of virulence factors are key pathogenic determinants of , causing a wide range of infectious diseases. Here, we characterized as a VraR-regulated gene encoding a cell wall inhibition-responsive protein (CwrA) using electrophoretic mobility shift assays. We constructed deletion mutants in the genetic background of methicillin-resistant (MRSA) and methicillin-sensitive (MSSA) strains.
View Article and Find Full Text PDFInfect Drug Resist
August 2024
Clinical Laboratory, Affiliated Hospital of Hangzhou Normal University, Hangzhou, 310015, People's Republic of China.
Mol Microbiol
August 2024
Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy.
The flagellar MS-ring, uniquely constituted by FliF, is essential for flagellar biogenesis and functionality in several bacteria. The aim of this study was to dissect the role of FliF in the Gram-positive and peritrichously flagellated Bacillus cereus. We demonstrate that fliF forms an operon with the upstream gene fliE.
View Article and Find Full Text PDFItal J Food Saf
May 2024
Department of Agricultural and Food Sciences, Alma Mater Studiorum University of Bologna, Ozzano dell'Emilia.
can harbor a broad repertoire of virulence and antimicrobial resistance (AMR) genes, which can be exchanged across the human gastrointestinal microflora, thus posing a public health risk. In this study, 6 batches of artisanal soft cheese and a 6-month ripened fermented dried sausage were investigated to assess the occurrence, phylogeny, and genomic traits (AMR, virulence, and mobilome) of . 30 and 3 strains isolated from salami and cheese food chains, respectively, were confirmed as by whole genome sequencing.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!