Biomedical subjects

C R Fuerst

Publications and source records attributed to C R Fuerst.

12 recordsLinked to original sources

PubMed1987

Indications of an involvement of heat-shock proteins in restoration of repression of temperative-inducible lambda prophage.

Characteristics of lambda c/ts857 prophages that can be attributed to the ability of the temperature-sensitive phage repressor to renature at low temperature are not apparent in host cells that contain a mutation in the htpR gene. Host killing by prophages that are N- or are blocked in DNA synthesis is not prevented by the return of mutant cells to low temperature, and recovery of cells in which the phage remains derepressed is not delayed if the prophage is a mutant that cannot kill. These and other findings suggest that the phage repressor protein is unusually susceptible to inactivation in cells that are unable to respond to heat shock.

Bacteriophage lambda↗

PubMed1986

Mutations in bacteriophage lambda that alter phage dependence on the htpR gene product of Escherichia coli.

Six mutants of lambda having reduced dependence on the htpR function of Escherichia coli were isolated from lambda cIts857. Burst sizes in htpRts cells at 40.5 degrees were in the range of 10 to 20 particles per cell. Mapping and complementation analysis of one of the mutants suggested that the mutation in this isolate is in gene J. Additional evidence that the mutations in most of the isolates are in J was provided by the finding that all but one of the mutants differ from the parental phage in properties pertaining to extended host range.

Bacterial Proteins↗

PubMed1985

Plating efficiencies of modified lambda bio particles on temperature-sensitive hsd mutants of Escherichia coli K12.

Two mutants of Escherichia coli K12 that are temperature sensitive in cell growth and lambda phage production are shown to contain at least two mutations. One of the mutations in each of the isolates is in the hsd locus, and modification and restriction of lambda exhibits temperature sensitivity. One of the hsd mutations causes plaque formation by modified lambda bio particles that do not contain an intact ral gene to be temperature dependent.

Bacteriophage lambda↗

PubMed1985

Involvement of the htpR gene product of Escherichia coli in phage lambda development.

Growth of phage lambda at high temperature requires a functional htpR host gene. The stages of the phage growth cycle shown to be dependent on htpR gene function include prophage excision and particle morphogenesis. Two types of morphogenetic abnormalities have been detected. One is a defect in phage tail assembly that results from a deficiency in tail fibers even though gpJ is produced. The severity of this defect is phage-strain specific. The second morphogenetic defect is less clearly defined, but results in formation of aberrant phage head structures. These abnormalities in lambda reproduction are presumed to be caused by the absence in htpR mutant host cells at high temperature of one or more of the heat-shock proteins of Escherichia coli whose synthesis is known to be regulated by the htpR gene.

Bacteriophage lambda↗

PubMed1985

Identification of a temperature-sensitive mutation in the htpR (rpoH) gene of Escherichia coli K-12.

A new mutation in the htpR (rpoH) gene of Escherichia coli K-12 was identified. The mutation resulted in a temperature-sensitive phenotype in terms of cell growth and bacteriophage lambda development. As in the case of the classical htpR tsn-165 mutation, synthesis of heat shock polypeptides was not induced in strains carrying the mutation described here.

Bacterial Proteins↗

PubMed1978