Stimulation of deoxyribonucleic acid replication fork movement by spermidine analogs in polyamine-deficient Escherichia coli.
AUTOR(ES)
Geiger, L E
RESUMO
We examined the rate of deoxyribonucleic acid (DNA) replication fork movement in polyamine-deficient cells of Escherichia coli by two independent techniques. DNA autoradiography was used to directly visualize the length of DNA produced during a given time interval, and replication rates were calculated. The amount of DNA synthesized after blocking protein synthesis also allowed calculation of replication rates. We found that the DNA chain elongation rate in polyamine-deficient cells was about half that of putrescine- or spermidine-supplemented cells. We also found that spermidine homologs of increasing chain length, when present at equal intracellular concentrations, exhibited a decreasing ability to support growth and the rate of DNA replication fork movement. The kinetics of recovery of DNA synthesis from the polyamine-deficient state were also investigated. A new rate of DNA synthesis was reached about 20 min after addition of spermidine to polyamine-limited cells. The rise in the rate of DNA synthesis was preceded by a rise in the intracellular concentration of spermidine.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=293810Documentos Relacionados
- Apparently unidirectional polyamine transport by proton motive force in polyamine-deficient Escherichia coli.
- Complementation of a polyamine-deficient Escherichia coli mutant by expression of mouse ornithine decarboxylase.
- Sensitivity of polyamine-deficient Saccharomyces cerevisiae to elevated temperatures.
- Polyamine-deficient Neurospora crassa mutants and synthesis of cadaverine.
- Spermidine-Deoxyribonucleic acid interaction in vitro and in Escherichia coli.