14 DAY TRIAL // A team of researchers at the University of Bristol, in the United Kingdom, announces the discovery of a new class of repair proteins. The molecules work in a network in such a way that they enable the microorganisms producing them to prioritize between various types of cellular repairs.
In other words, if a bacteria is experiencing several types of DNA damage at the same time, for example, this protein network will enable it to select which of the harm it would like to address first.
This priority mechanism is tremendously important if the microbes come under swift attack, and DNA survival become the main objective. Using these proteins, the organism can get to work right away, rather than having to wait for other cellular repair tasks to be completed.
In experiments conducted at the university, the research team learned that the areas mostly favored for repair are those DNA regions that contain the most critically-important information which the bacteria needs for its very survival.
From an evolutionary perspective, this trait makes absolute sense. Bacteria that prioritized other types of repairs where killed whenever they came under sudden and swift attack.
The new investigation adds additional credence to past proposals suggesting that the bacteria and human DNA repair systems have a lot in common.
Details of the work are published in the December issue of the esteemed journal Molecular Cell.
Repairing the genetic material is important because damage to the four “letters” making up DNA may cause the cell to function improperly. Deoxyribonucleic acid can be damaged through a wide variety of means, geneticists say.
In humans, the ultraviolet component of sunlight may cause DNA damage in skin cells, triggering the development and subsequent spread of cancer tumors.
All organisms living on Earth figured out that this type of damage cannot be avoided since they first appeared here, which is why all of them developed advanced repair mechanisms.
“The repair systems need molecular machines that can detect the DNA damage in the first place, machines that can cut away the damaged DNA, and machines that can finish the repair by building new undamaged DNA,” UB experts say.
“All of these molecular machines must work together in an organized fashion to carry out these very intricate repairs, and so they also require machines that take the part of foreman and co-ordinate the work of the others,” they add.
“This work is an example of 'basic research,' it is a fundamental study of the molecular mechanisms of an important biological function that is conserved from bacteria to man, and was begun in a spirit of scientific exploration rather than with a view to an immediate technological or medical application,” says Dr. Nigel Savery.
“However, like all basic research it provides the foundation of knowledge upon which technological and medical advances are built,” adds the expert, who led the UB team.
“In this case the work provides knowledge and experimental tools that may help to explain how this transcription-coupled DNA repair pathway, which normally prevents mutation, acts to increase the frequency with which antibiotic-resistant mutants of bacteria involved in food poisoning arise,” he adds.
The group that found the proteins is based at UB School of Biochemistry' DNA-Protein Interactions Unit. The Biotechnology and Biological Sciences Research Council (BBSRC) funded the study.