Biomaterial Database

Development of bacteriophage Ha2, a phiX174 derivative, in Escherichia coli strains carrying a thermosensitive mutation in the dnaG gene. 1975

N Truffaut, and I Manheimer

Ha2 is a derivative of HaHb, a phiX174 mutant able to grow on several Escherichia coli K 12 strains which are insensitive to phiX174 wild type. Ha2 was isolated after nitrous acid mutagenesis and selected as being able to give large plaques in equal number at 42 degrees C as well as 30 degrees C when plated on Escherichia coli C and CR34. Hosts carrying a thermosensitive mutation at the dnaG locus are unable to support the replication and maturation of Ha2 at the restrictive temperature. The first steps of Ha2 development: attachment, eclipse and penetration, are not affected by the dnaG mutation. The viral DNA penetrates the cell as single-strands, which are probably attached to a viral protein component. The following steps of viral replication depend on the presence of an active dnaG gene product: no formation of parental RF; no synthesis and replication of progeny RF were observed in the mutant strains at 42 degrees C. The synthesis of viral single-stranded DNA as well as phage formation are lowered after a shift to the restrictive conditions, suggesting that the dnaG gene product is also involved at these stages.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
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
D011402	Pronase	A proteolytic enzyme obtained from Streptomyces griseus.	Pronase E,Pronase P,Protease XIV,XIV, Protease
D003090	Coliphages	Viruses whose host is Escherichia coli.	Escherichia coli Phages,Coliphage,Escherichia coli Phage,Phage, Escherichia coli,Phages, Escherichia coli
D004269	DNA, Bacterial	Deoxyribonucleic acid that makes up the genetic material of bacteria.	Bacterial DNA
D004277	DNA, Single-Stranded	A single chain of deoxyribonucleotides that occurs in some bacteria and viruses. It usually exists as a covalently closed circle.	Single-Stranded DNA,DNA, Single Stranded,Single Stranded DNA
D004279	DNA, Viral	Deoxyribonucleic acid that makes up the genetic material of viruses.	Viral 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
D012367	RNA, Viral	Ribonucleic acid that makes up the genetic material of viruses.	Viral RNA