Biomaterial Database

Escherichia coli mut T1. II. Consequences of modification on the association of DNA with the cell membrane. 1979

T Campana, and H S Shapiro

1. Two isogenic strains of Escherichia coli, K-12 which differ by mutator gene character (mut T1) have been studied. This characteristic caused introduction of a high frequency of undirectional transversions, A-T leads to -CG, into the DNA of the strain harboring it. 2. It had been previously shown that the presence of this gene is accompanied by an alteration of a cell membrane component. Now, the nuclease susceptibility of DNA associated with membrane/DNA/DNA polymerase complexes is reported. DNA of mut T1 membranes is more sensitive towards exogenous nuclease than DNA of membrane complexes from the wild type mut+ strain. 3. Auto-digestion of this DNA by endogenous nuclease associated with the membrane complex is, also, more severe in preparations derived from mut T1 than from the wild-type strain, mut+, but to a lesser extent than observed with exogenous nucleases. 4. Nuclease susceptibility of mut+ membrane bound DNA is markedly influenced by the growth state of the cell. The nuclease susceptibility of membrane bound DNA from mut T1 cells, however, shows no differences between stationary and log states. 5. These differential sensitivities may be due to conformational changes in the membrane introduced as a pleiotrophic consequence of an altered membrane protein. A pertinent role of this protein in a modified replication/repair complex is an attractive suggestion, especially in the context of the mutator character of this strain.

UI	MeSH Term	Description	Entries
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
D009690	Nucleic Acid Conformation	The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.	DNA Conformation,RNA Conformation,Conformation, DNA,Conformation, Nucleic Acid,Conformation, RNA,Conformations, DNA,Conformations, Nucleic Acid,Conformations, RNA,DNA Conformations,Nucleic Acid Conformations,RNA Conformations
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D003851	Deoxyribonucleases	Enzymes which catalyze the hydrolases of ester bonds within DNA. EC 3.1.-.	DNAase,DNase,Deoxyribonuclease,Desoxyribonuclease,Desoxyribonucleases,Nucleases, DNA,Acid DNase,Alkaline DNase,DNA Nucleases,DNase, Acid,DNase, Alkaline
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
D013045	Species Specificity	The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.	Species Specificities,Specificities, Species,Specificity, Species