Biomaterial Database

Divergent orientation of transcription from the arginine gene ECBH cluster of Escherichia coli. 1974

C J Panchal, and S N Bagchee, and A Guha

Ribonucleic acid (RNA) isolated from Escherichia coli W3350 (F(-), argE(+)C(+)B(+)H(+)), in the absence of l-arginine, hybridizes with the separated leftward (l) and rightward (r) transcribing strands of the arginine transducing phage hphi80dargE(+)C(+)B(+)H(+)ppc(+)imm(lambdacI857) deoxyribonucleic acid (DNA) with a ratio of 30:70, respectively. In the presence of l-arginine and its intermediates, l-ornithine and l-citrulline, RNA transcriptions from both the strands of the argECBH cluster were repressed. The derepressed RNA, when hybridized with the separated strands of hphi80dargEC-I imm(lambda) phage DNA (the arginine genes are inversely inserted in this phage), which has a deletion in gene E and extends to gene C of the argECBH cluster, showed no leftward transcription, whereas the rightward transcription was reduced to about 40% of that when the DNA carrying the entire ECBH cluster was used for hybridization. The hybridization results thus demonstrate that (i) the regulation of the argECBH gene cluster in E. coli is under transcriptional control, (ii) the orientation of transcription is divergent, (iii) E gene transcribes anticlockwise, whereas the rest of the genes, C, B, and H, transcribe clockwise, and (iv) the position of the promoter(s) and operator(s) is located between the E and C genes of the argECBH cluster.

UI	MeSH Term	Description	Entries
D008242	Lysogeny	The phenomenon by which a temperate phage incorporates itself into the DNA of a bacterial host, establishing a kind of symbiotic relation between PROPHAGE and bacterium which results in the perpetuation of the prophage in all the descendants of the bacterium. Upon induction (VIRUS ACTIVATION) by various agents, such as ultraviolet radiation, the phage is released, which then becomes virulent and lyses the bacterium.	Integration, Prophage,Prophage Integration,Integrations, Prophage,Prophage Integrations
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D009693	Nucleic Acid Hybridization	Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)	Genomic Hybridization,Acid Hybridization, Nucleic,Acid Hybridizations, Nucleic,Genomic Hybridizations,Hybridization, Genomic,Hybridization, Nucleic Acid,Hybridizations, Genomic,Hybridizations, Nucleic Acid,Nucleic Acid Hybridizations
D009952	Ornithine	An amino acid produced in the urea cycle by the splitting off of urea from arginine.	2,5-Diaminopentanoic Acid,Ornithine Dihydrochloride, (L)-Isomer,Ornithine Hydrochloride, (D)-Isomer,Ornithine Hydrochloride, (DL)-Isomer,Ornithine Hydrochloride, (L)-Isomer,Ornithine Monoacetate, (L)-Isomer,Ornithine Monohydrobromide, (L)-Isomer,Ornithine Monohydrochloride, (D)-Isomer,Ornithine Monohydrochloride, (DL)-Isomer,Ornithine Phosphate (1:1), (L)-Isomer,Ornithine Sulfate (1:1), (L)-Isomer,Ornithine, (D)-Isomer,Ornithine, (DL)-Isomer,Ornithine, (L)-Isomer,2,5 Diaminopentanoic Acid
D010761	Phosphorus Radioisotopes	Unstable isotopes of phosphorus that decay or disintegrate emitting radiation. P atoms with atomic weights 28-34 except 31 are radioactive phosphorus isotopes.	Radioisotopes, Phosphorus
D002499	Centrifugation, Density Gradient	Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Centrifugations, Density Gradient,Density Gradient Centrifugation,Density Gradient Centrifugations,Gradient Centrifugation, Density,Gradient Centrifugations, Density
D002874	Chromosome Mapping	Any method used for determining the location of and relative distances between genes on a chromosome.	Gene Mapping,Linkage Mapping,Genome Mapping,Chromosome Mappings,Gene Mappings,Genome Mappings,Linkage Mappings,Mapping, Chromosome,Mapping, Gene,Mapping, Genome,Mapping, Linkage,Mappings, Chromosome,Mappings, Gene,Mappings, Genome,Mappings, Linkage
D002956	Citrulline
D003090	Coliphages	Viruses whose host is Escherichia coli.	Escherichia coli Phages,Coliphage,Escherichia coli Phage,Phage, Escherichia coli,Phages, Escherichia coli
D004279	DNA, Viral	Deoxyribonucleic acid that makes up the genetic material of viruses.	Viral DNA