Biomaterial Database

Na+/H+ antiport activity conferred by Bacillus subtilis tetA(L), a 5' truncation product of tetA(L), and related plasmid genes upon Escherichia coli. 1996

J Cheng, and K Baldwin, and A A Guffanti, and T A Krulwich

Department of Biochemistry, Mount Sinai School of Medicine, City University of New York, New York 10029, USA.

An Escherichia coli transformant expressing the Bacillus subtilis tetA(L) gene from a weak promoter was challenged by growth on medium with low, increasing tetracycline concentrations. Changes in the substrate preference ratios of the TetA(L)-mediated resistances and antiports were examined in view of recent findings suggesting that TetA(L) catalyzes efflux of Na+ in exchange for protons in addition to having the ability to catalyze metal-tetracycline/H+ antiport. After growth of the transformant on 1 microgram or more of tetracycline per ml for 12 to 15 h, the tetA(L) gene in the plasmid was found to be disrupted by an IS10 element 50 bp from the 5' end of the coding sequence. This disrupted recombinant plasmid, pKB1, conferred greater tetracycline resistance and higher levels of membrane metal-tetracycline/proton antiport than the original plasmid, pJTA1, but conferred lower NA+ resistance and Na+/H+ antiport levels than the original plasmid. The results indicate that the 5' end of the gene is necessary for optimal Na+/H+ antiport but that some such activity as well as robust tetracycline/H+ antiport persists in its absence. Two plasmid genes, tet(K) and qacA, were compared with tetA(L) vis-à-vis their abilities to enhance the Na+/H+ antiporter activity of everted vesicles from E. coli transformants. tet(K), which is more closely related to tetA(L), catalyzed 22Na+ uptake by energized vesicles, whereas the less closely related qacA gene did not.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D011815	R Factors	A class of plasmids that transfer antibiotic resistance from one bacterium to another by conjugation.	R Factor,R Plasmid,R Plasmids,Resistance Factor,Resistance Factors,Factor, R,Factor, Resistance,Factors, R,Factors, Resistance,Plasmid, R,Plasmids, R
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D001412	Bacillus subtilis	A species of gram-positive bacteria that is a common soil and water saprophyte.	Natto Bacteria,Bacillus subtilis (natto),Bacillus subtilis subsp. natto,Bacillus subtilis var. natto
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA
D013752	Tetracycline	A naphthacene antibiotic that inhibits AMINO ACYL TRNA binding during protein synthesis.	4-Epitetracycline,Achromycin,Achromycin V,Hostacyclin,Sustamycin,Tetrabid,Tetracycline Hydrochloride,Tetracycline Monohydrochloride,Topicycline,4 Epitetracycline
D013753	Tetracycline Resistance	Nonsusceptibility of bacteria to the action of TETRACYCLINE which inhibits aminoacyl-tRNA binding to the 30S ribosomal subunit during protein synthesis.
D017923	Sodium-Hydrogen Exchangers	A family of plasma membrane exchange glycoprotein antiporters that transport sodium ions and protons across lipid bilayers. They have critical functions in intracellular pH regulation, cell volume regulation, and cellular response to many different hormones and mitogens.	Na(+)-H(+)-Antiporter,Na(+)-H(+)-Exchanger,Sodium-Hydrogen Antiporter,Na(+)-H(+)-Antiporters,Na(+)-H(+)-Exchangers,SLC9 Na(+)-H(+) Exchangers,SLC9 Protein Family,SLC9 Proteins,SLC9-NHE Protein Family,Sodium-Hydrogen Antiporters,Sodium-Hydrogen Exchanger,Sodium-Proton Antiporter,Sodium-Proton Antiporters,Solute Carrier 9 Protein Family,Solute Carrier 9 Proteins,Antiporter, Sodium-Hydrogen,Antiporter, Sodium-Proton,Antiporters, Sodium-Hydrogen,Antiporters, Sodium-Proton,Exchanger, Sodium-Hydrogen,Exchangers, Sodium-Hydrogen,Protein Family, SLC9,Protein Family, SLC9-NHE,SLC9 NHE Protein Family,Sodium Hydrogen Antiporter,Sodium Hydrogen Antiporters,Sodium Hydrogen Exchanger,Sodium Hydrogen Exchangers,Sodium Proton Antiporter,Sodium Proton Antiporters