Intentional biological repair mechanisms

E coliThere’s no point in paraphrasing what has already been well expressed. Below we reproduce a digest of recent research into bacteria repair proteins – proteins that not only enable bacteria to repair damaged DNA but to prioritise the repairs according to what is most urgent. We have long known that, left to themselves, ordered systems degenerate over time. It is a universal law, encapsulated in the second law of thermodynamics. But life, for a time, counteracts it. Indeed, the DNA code expressly includes mechanisms for counteracting it. How can Nature contradict itself in this way?

The theory of evolution argues that the universe is godless, that the fantastically complex biological programs which govern embryonic development and cell maintenance are uncaused accidents, and that accidental mutations of the programs are the stuff of creation. But genomes themselves resist such aberrations. They do so because accidental mutations do not increase information content or level of organisation. They are frequently lethal.
When the chemical ‘letters’ in a cell’s DNA book of instructions are damaged the instructions become difficult to read and the cell may not function properly. For example, exposure to too much sunshine increases the risk of skin cancer because the ultraviolet light present in sunshine damages the DNA in skin cells and can cause them to grow in an abnormal way.
Because it is impossible to avoid DNA damage, cells have evolved many mechanisms for repairing their damaged genomes. Like council crews repairing damaged roads these DNA repair mechanisms employ individuals with different specialities: sometimes all that is needed is a small patch on the DNA, like filling in a pothole, other times large sections of the DNA need to be removed entirely and replaced.
The repair systems need molecular machines that can detect the DNA damage in the first place, cut away the damaged DNA, and finish the repair by building new undamaged DNA. All these machines must work together in an organised fashion to carry out these very intricate repairs, so they also require machines that take the part of foreman and co-ordinate the work of the others.
When DNA is heavily damaged, cells ensure that the sections that need to be read for instructions (in a process called transcription) are repaired before sections that aren’t being read.
A team led by Dr. Nigel Savery from the DNA-Protein interactions Unit in the University of Bristol’s School of Biochemistry has purified each of the many individual components of this ‘transcription-coupled’ DNA repair pathway from the bacterium Escherichia coli and rebuilt the system in a test-tube. This allowed them to investigate the effects of disabling different parts of the different machines and hence work out what is required to prioritise certain sections of DNA for repair. The team found that different proteins take responsibility for spotting damage in different situations, and that one of the machines can turn itself off when it is not working, in order to decrease the ‘fuel consumption’ of the system.

The original ScienceDaily report, along with details of the underlying paper, may be found here.

It may seem inconceivable that genomes can actively counteract events that impair their functionality and anticipate such events before they have happened, but that is what microbiological research reveals. Natural things have the quality of the inconceivable because they are products of creation. According to his own testimony, only God knows from the beginning what is yet to be (Isaiah 46:10). He alone can do what is impossible.

If you have not made your peace with him, you need to, for he knows the beginning and end of your life too. For ‘just as it is appointed for man once to die, and after that, judgement, so Christ, having been once offered to bear the sins of many, will appear a second time, without sin, to save those waiting for his salvation’. Ultimate reality is not what we see with our eyes but the invisible Maker of the universe.