ABSTRACT Acinetobacter baumannii possesses a single divergent luxR / luxRI -type quorum-sensing (QS) locus named abaR abaI . This also contains third gene located between and , which we term abaM that codes for an uncharacterized member of the RsaM protein family known to regulate N -acylhomoserine lactone (AHL)-dependent QS in other beta- gammaproteobacteria. Here, show disruption via T26 inse...

mara activates two membrane dependent mechanisms of resistance to different antibiotics, such as ciprofloxacin and tetracycline, including promotion of outflux and inhibition of influx of antibiotics. thus, mara causes multiple antibiotic resistance phenotype. the activation of these mechanisms needs overexpression of mara. this could happen through mutation in marr. thus, the aim of this study...

conclusions the results of the antibiotic resistance and other data suggest that there is a possible common clone of e. faecalis, which could rapidly disseminate in patients and the environment. results the results indicated that, 86% of patient and 29% of environmental isolates carried ebp genes. the ability of the isolates to strongly attach was 62% and 71% for patient and environmental sampl...

knowing the nucleotide sequence of the cholera toxin operon, we designed oligonucleotide primers for its-pcr amplification from local clinical isolates of v. cholerae. the resulting amplification product was cloned in a common puc18 vector. subsequently, a part of this operon encoding the cholera toxin bsubunit (ctb) was reamplified and cloned between the bamh1 and ecor1 sites of the same vecto...

The physiological importance of translational regulation in controlling the synthesis of ribosomal proteins from the L11 ribosomal protein operon was determined for the classical regulatory phenomena of growth rate dependence and stringent control. Translational regulation of the L11 operon by ribosomal protein L1, the L11 operon-specific translational repressor protein, was abolished by introd...

The cob operon encodes functions needed for the biosynthesis of adenosylcobalamin (Ado-B12). Propanediol induces transcription of the cob operon and the neighboring pdu operon, which encodes proteins for the B12-dependent degradation of propanediol. Expression of the cob (but not the pdu) operon is repressed by exogenous cyanocobalamin. Evidence is provided that cob operon repression is signale...

The expression of the Kdp system for K+ uptake in Escherichia coli requires the products of two genes, kdpD and kdpE. These genes constitute an operon adjacent to the kdpABC operon that encodes the three membrane protein subunits of Kdp. Both operons are transcribed in the same direction and overlap; the kdpDE promoter is in kdpC, the last gene of the kdpABC operon. Transcription of the kdpDE o...

For most organisms, computational operon predictions are the only source of genome-wide operon information. Operon prediction methods described in literature are based on (a combination of) the following five criteria: (i) intergenic distance, (ii) conserved gene clusters, (iii) functional relation, (iv) sequence elements and (v) experimental evidence. The performance estimates of operon predic...

Operons are widespread in prokaryotes, but are uncommon in eukaryotes, except nematode worms, where approximately 15% of genes reside in over 1100 operons in the model organism Caenorhabditis elegans. It is unclear how operons have become abundant in nematode genomes. The "one-way street" hypothesis asserts that once formed by chance, operons are very difficult to break, because the breakage wo...