Molecular analysis and nucleotide sequence of the envCD operon of Escherichia coli

Klein, Jürgen; Henrich, Bernhard; Plapp, Roland

doi:10.1007/bf00290673

Cited by 80 publications

(64 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All of these are so-called membrane fusion proteins (MFPs) of RNDtype multidrug efflux transporters. The analysis also showed VmeB to share 63, 63, 62, 62 and 61 % identities, respectively, with AcrB, AcrD and AcrF of E. coli (Klein et al, 1991;Ma et al, 1993Ma et al, , 1994, SdeY of S. marcescens (Chen et al, 2003) and MexB of P. aeruginosa (Poole et al, 1993). These are inner-membrane proteins of RND-type multidrug efflux transporters.…”

Section: Sequencingmentioning

confidence: 94%

“…All these differences were translationally silent, except two: changing amino acid residue Gly33 in VP1091 to Ala33 in VmeA, and changing Ala1046 in VP1092 to Asp1046 in VmeB. A BLAST search for protein sequence similarities (NCBI) showed VmeA to share, respectively, 49, 49, 47 and 46 % identities with AcrA and AcrE of E. coli (Klein et al, 1991;Ma et al, 1993), SdeX of Serratia marcescens (Chen et al, 2003) and MexA of Pseudomonas aeruginosa (Poole et al, 1993). All of these are so-called membrane fusion proteins (MFPs) of RNDtype multidrug efflux transporters.…”

Section: Sequencingmentioning

confidence: 99%

See 1 more Smart Citation

VmeAB, an RND-type multidrug efflux transporter in Vibrio parahaemolyticus

et al. 2007

View full text Add to dashboard Cite

Genes vmeA and vmeB, encoding a multidrug efflux transporter in the halophilic bacterium Vibrio parahaemolyticus, have been cloned using a drug-hypersusceptible Escherichia coli strain as the host. Cells of E. coli KAM33 (DacrAB DydhE) carrying the vmeAB region from V. parahaemolyticus conferred much higher MICs for a variety of antimicrobial agents than did control cells. Cells possessing VmeAB under energized conditions maintained very low intracellular concentrations of ethidium. This was as expected for an energy-dependent efflux system, and supports the notion -based on sequence homology -that VmeAB belongs to the resistance nodulation cell division (RND) family of multidrug efflux transporters. It is likely that VmeAB forms functional complexes with the outer-membrane protein TolC in E. coli, because introduction of vmeAB into cells of E. coli KAM43, which lacks the tolC gene, failed to elevate the MICs for any of the antimicrobial agents tested. Therefore, a V. parahaemolyticus homologue of tolC was also cloned, designated vpoC, and was introduced together with vmeAB into cells of E. coli KAM43. The MICs of all agents tested were raised and were comparable to the values observed in E. coli KAM33 harbouring a plasmid carrying vmeAB. Finally, a vmeAB-deficient mutant of V. parahaemolyticus was constructed (designated TM3). TM3 showed slightly higher susceptibility than the parental V. parahaemolyticus to some antimicrobial agents. Survival rate of the TM3 when exposed to deoxycholate decreased compared with that of the parent. INTRODUCTIONVibrio parahaemolyticus, a slightly halophilic marine bacterium, is a major cause of food poisoning in Japan (Obata et al., 2001; WHO, 1999;Yamazaki et al., 2003) and many other countries (Cabanillas-Beltran et al., 2006; CDC, 2006;Lozano-Leon et al., 2003;McLaughlin et al., 2005; Sen et al., 2007;Su et al., 2005a). The organism has some peculiar physiological characteristics, such as a very fast growth rate, a Na + requirement for growth (Baumann & Schubert, 1984) and an ability to live in diverse environments including brackish water (Kumazawa & Kato, 1985), on estuarine algae (Kumazawa et al., 1991), and in mammalian hosts, including humans (Yamamoto & Yokota, 1989).In achieving human infection, V. parahaemolyticus survives in the intestine and especially in the duodenum, where bile acids and their conjugates are abundant. Bile acids are anionic detergents and support the digestion of fats in the intestine. In addition, bile has bactericidal effects due to its membrane-solvent property (Provenzano et al., 2000). Thus, bile resistance of enteropathogenic bacteria is thought to be important for their survival in the intestine. Some enteropathogenic bacteria have been shown to possess systems to protect from the actions of bile. In the case of Vibrio cholerae, the outer-membrane component TolC Vc , which had already been identified as a component of some multidrug efflux transporters (sometimes called multidrug efflux pumps), was found to contribute to resistance to bile,...

show abstract

Section: Sequencingmentioning

confidence: 94%

Section: Sequencingmentioning

confidence: 99%

VmeAB, an RND-type multidrug efflux transporter in Vibrio parahaemolyticus

et al. 2007

View full text Add to dashboard Cite

show abstract

“…Kohara X phage clones KiSO, K1Sl, and K530 were kindly provided by Fred Blattner (University of Wiscortsin). KlSO and K1S1 span the 10.5-min region of the E. coli chromosome (17,26,39), and K530 has been previously mapped by hybridization to contain envCD (15). To isolate acrA, KlSO and K1S1 were subcloned into either pUC19 or pBR322 to generate plasmids pUCK1SOA, pBRK1SOB, pUCKlSlA, pBRK1S1B, and pUCKlSlC ( Fig.…”

Section: Methodsmentioning

confidence: 99%

Molecular cloning and characterization of acrA and acrE genes of Escherichia coli

et al. 1993

View full text Add to dashboard Cite

show abstract

“…The former gene encodes a positively acting transcription factor similar to the OmpR-PhoB superfamily of response regulators (Gross et al, 1989) and thus the SARP proteins (Wietzorrek & Bibb, 1997), whilst the jadR2 gene encodes a negatively acting repressor protein similar to known repressors like EnvR (Klein et al, 1991), TetC (Scholtmeier & Hillen, 1984) and TcmR (Guilfoile & Hutchinson, 1992). Disruption of jadR2 relieves the stress response needed to induce jadomycin production in the wild-type strain, and when a jadR2 mutant is cultured under stressful conditions (heat shock or toxic concentrations of ethanol), jadomycin is overproduced (Yang et al, 1995).…”

Section: Discussionmentioning

confidence: 99%

The dnrO gene encodes a DNA-binding protein that regulates daunorubicin production in Streptomyces peucetius by controlling expression of the dnrN pseudo response regulator gene

2000

View full text Add to dashboard Cite

The dnrO gene is located adjacent to and divergently transcribed from the response regulator gene, dnrN, that activates the transcription of the dnrI gene, which in turn activates transcription of the daunorubicin biosynthesis genes in Streptomyces peucetius. Gene disruption and replacement of dnrO produced the dnrO ::aphII mutant strain and resulted in the complete loss of daunorubicin biosynthesis. Suppression of the dnrO ::aphII mutation by the introduction of dnrN or dnrI on a plasmid suggested that DnrO is required for the transcription of dnrN, whose product is known to be required for dnrI expression. These conclusions were supported by the effects of the dnrO mutation on expression of dnrO, dnrN and dnrI, as viewed by melC fusions to each of these regulatory genes. DnrO was overexpressed in Escherichia coli and the cell-free extract was used to conduct mobility shift DNA-binding assays. The results showed that DnrO binds specifically to the overlapping dnrN/dnrO p1 promoter region. Thus, DnrO may regulate the expression of both the dnrN and dnrO genes.

show abstract

Molecular analysis and nucleotide sequence of the envCD operon of Escherichia coli

Cited by 80 publications

References 49 publications

VmeAB, an RND-type multidrug efflux transporter in Vibrio parahaemolyticus

VmeAB, an RND-type multidrug efflux transporter in Vibrio parahaemolyticus

Molecular cloning and characterization of acrA and acrE genes of Escherichia coli

The dnrO gene encodes a DNA-binding protein that regulates daunorubicin production in Streptomyces peucetius by controlling expression of the dnrN pseudo response regulator gene

Contact Info

Product

Resources

About