Biomaterial Database

High resolution experimental and theoretical thermal denaturation studies on small overlapping restriction fragments containing the Escherichia coli lactose genetic control region. 1981

W Hillen, and T C Goodman, and A S Benight, and R M Wartell, and R D Wells

The distribution of thermal stability in the Escherichia coli lac control region is evaluated from the melting behavior of 5 short (80-219 base pairs (bp)) sequenced DNA restriction fragments containing various parts of this sequence. The thermal denaturation of these fragments was measured at 3 salt concentrations. The previous notion that the melting curves for small fragments are sharp and asymmetric in 0.01 M Na+ and broadened and less asymmetric at 0.105 and 0.505 M Na+ is confirmed and the possible explanations are discussed. The existence of two thermodynamic boundaries in this region is also confirmed. The exact location of the boundary upstream of the cyclic AMP receptor protein (CAP) binding site is accurately determined from melting experiments at 260 and 282 nm. The secondary boundary located between the promoter and operator sequence is apparent at the two higher salt concentrations and begins to disappear at the lower salt concentration. The physical interpretation of the melting experiments is compared to the results of theoretical predictions derived from the known sequence of the fragments.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D007785	Lactose	A disaccharide of GLUCOSE and GALACTOSE in human and cow milk. It is used in pharmacy for tablets, in medicine as a nutrient, and in industry.	Anhydrous Lactose,Lactose, Anhydrous
D009691	Nucleic Acid Denaturation	Disruption of the secondary structure of nucleic acids by heat, extreme pH or chemical treatment. Double strand DNA is "melted" by dissociation of the non-covalent hydrogen bonds and hydrophobic interactions. Denatured DNA appears to be a single-stranded flexible structure. The effects of denaturation on RNA are similar though less pronounced and largely reversible.	DNA Denaturation,DNA Melting,RNA Denaturation,Acid Denaturation, Nucleic,Denaturation, DNA,Denaturation, Nucleic Acid,Denaturation, RNA,Nucleic Acid Denaturations
D004262	DNA Restriction Enzymes	Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.	Restriction Endonucleases,DNA Restriction Enzyme,Restriction Endonuclease,Endonuclease, Restriction,Endonucleases, Restriction,Enzymes, DNA Restriction,Restriction Enzyme, DNA,Restriction Enzymes, DNA
D004269	DNA, Bacterial	Deoxyribonucleic acid that makes up the genetic material of bacteria.	Bacterial DNA
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
D005796	Genes	A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.	Cistron,Gene,Genetic Materials,Cistrons,Genetic Material,Material, Genetic,Materials, Genetic
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
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures