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Cells can read damaged DNA without missing a beat
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Wednesday, 10 February 2010 15:53 |
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WASHINGTON – Every cell has DNA-reading machinery that can skim through certain kinds of damaged DNA without skipping any letters in the genetic "text."
The studies, performed in bacteria, suggest a new way for bacteria to develop resistance to antibiotics.
The results were published online this week in the Proceedings of the National Academy of Sciences.
In the studies, researchers examined the ability of RNA polymerase (the enzyme that transcribes, or makes RNA from DNA) to handle damaged DNA templates.
Surprised by adaptability
RNA polymerase reads one strand of the double helix and assembles RNA that is complementary to that strand. In test tube experiments, when the enzyme comes to a gap or a blank space, it keeps reading but leaves out letters across from the damaged stretch. In contrast, in cells, RNA polymerase puts a random letter (preferring A) across from the gap.
"We were surprised to find that the transcription machinery rolls right over the damaged portion," said biochemistry professor Dr Paul Doetsch of Emory University School of Medicine.
"This shows that if the cell initiates, but doesn't complete repair, it still can lead to mutagenesis."
According to ScienceDaily, a US-based science news website, the next phase of studies for Doetsch and colleagues will be to test whether transcriptional mutation can lead directly to antibiotic resistance in bacteria and other microorganisms.
The research was supported by the National Institutes of Health.
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Last Updated on Wednesday, 10 February 2010 16:08 |
