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Periodate inhibition of transformation and competence development in Haemophilus influenzae
Insights
Periodate treatment significantly inhibits bacterial transformation and competence development in Haemophilus influenzae by targeting DNA binding sites, not the DNA itself.
Area of Science:
- Microbiology
- Molecular Biology
- Bacteriology
Background:
- Bacterial transformation is a key mechanism for genetic exchange.
- Competence development is essential for bacteria to uptake exogenous DNA.
- Understanding factors that regulate transformation is crucial for microbial genetics.
Purpose of the Study:
- To investigate the inhibitory effects of periodate on bacterial transformation.
- To determine the mechanism by which periodate affects competence development in Haemophilus influenzae.
- To identify the cellular component sensitive to periodate inhibition.
Main Methods:
- Treatment of competent Haemophilus influenzae cells with periodate.
- Assessing transformation frequency to streptomycin resistance.
- Evaluating cell viability post-treatment.
- Investigating periodate's effect at different stages of competence development.
- Testing periodate's impact on transforming DNA and DNA-cell interactions.
Main Results:
- Periodate treatment reduced transformation frequency by approximately 90% with minimal impact on cell viability.
- Inhibition of competence development occurred when periodate was added early in the competence phase.
- Periodate did not affect transforming DNA or its interaction with already competent cells.
- The inhibition was not genetic, as progeny from inactivated cells could achieve full competence.
Conclusions:
- Periodate acts as an inhibitor of transformation and competence development in Haemophilus influenzae.
- The sensitive target of periodate is likely related to the DNA binding site(s) rather than the DNA molecule itself.
- These findings suggest a specific role for the cell's DNA uptake machinery in periodate sensitivity.
Abstract:
Ranhand, Jon M. (University of Cincinnati, Cincinnati, Ohio), and Herman C. Lichstein. Periodate inhibition of transformation and competence development in Haemophilus influenzae. J. Bacteriol. 92:956-959. 1966.-Periodate treatment of competent cells reduced the frequency of transformation to streptomycin resistance about 90% while reducing cell viability about 30% or less. Moreover, when periodate was added to cells early in the competence-development phase, these, too, were unable to develop maximal competence. Periodate inhibition was dependent on time and concentration as well as on the composition of the suspending menstruum. Periodate had no effect on transforming deoxyribonucleic acid (DNA), nor did it prevent transformation when added to competent cells which had already reacted with DNA. Furthermore, the progeny from cells inactivated 90% could be made fully competent, showing that the inhibition was not genetic. It was concluded that the periodate-sensitive substrate may involve the DNA binding site(s).