Electric DNA
by Jonathan Sarfati
Creation magazine has shown how DNA is the ultimate information storage
molecule in the universe.1
We also showed how cutting-edge discoveries refute the idea of ‘junk’
DNA, which doesn’t code for proteins, showing that this has an amazing array
of functions that we are only just beginning to learn about. Dr John Mattick, a
leading researcher into DNA function, proposes that ‘junk’ DNA acts
like an advanced computer operating system.1 More recently, he lamented
how the idea that non-protein–coding DNA was just junk had greatly harmed
science:
Photo <www.stockxpert.com>
‘The failure to recognize the full implications of [non-protein–coding
DNA] may well go down as one of the biggest mistakes in the history of molecular
biology.’2
Electric protection
Another intriguing property is how DNA in cells conducts electricity.1,3 DNA is easily damaged. Some chemicals, including
free radicals, attack DNA by stealing an electron from (i.e. oxidizing) one of the
bases—the chemical ‘letters’ of the DNA code. The resulting electron
‘hole’ can hop along the DNA, behaving like a positive electric current.
We already reported that some of the ‘junk’ DNA comprises pairings between
the ‘letters’ A and T (the bases adenine
and thymine), and this blocks this damaging electrical current. These pairings act
as insulators or ‘electronic hinges in a circuit’ to protect essential
genes from electrical damage from free radicals attacking a distant part of the
DNA.1
More recently, Jacqueline Barton of the California Institute of Technology has shown
that DNA also uses its electrical properties for protection. At the edge of some
genes, there is a string of G ‘letters’ (the base guanine).
They readily absorb the electron hole, so the electron hole moves along until it
reaches this string of Gs. This deflects the damage from the parts
of the DNA that code for proteins.4
This is very much like the principle behind galvanized iron. Here, a coating of
a more reactive and less important metal, zinc, sacrificially takes all the oxidation,
thus protecting the iron from rusting.
DNA errors are scanned electrically
Such ingenious repair machinery must have been present in all life right from the beginning.
Our cells have elaborate machinery to repair DNA. But with 3 billion ‘letters’
worth of information in every cell, there is a lot to scan for errors.
However, unbroken DNA conducts electricity, while an error blocks the current. Now
Dr Barton has found that some repair enzymes exploit this. One pair of enzymes lock
onto different parts of a DNA strand. One of them sends an electron down the strand.
If the DNA is unbroken, the electron reaches the other enzyme, and causes it to
detach. I.e. this process scans the region of DNA between them, and if it’s
clean, there is no need for repairs.
But if there is a break, the electron doesn’t reach the second enzyme. This
enzyme then moves along the strand until it reaches the error, and fixes it. This
mechanism of repair seems to be present in all living things, from bacteria to man.5
Such ingenious repair machinery must have been present in all life right from the
beginning, otherwise life could not have survived breaks in its DNA. As scientists
discover more of the intricate design of life, we can see more how we are ‘fearfully
and wonderfully made’ (Psalm 139:14).
Pseudogene not so pseudo
One of the main categories of ‘junk’ DNA is ‘pseudogenes’.
Evolutionists claim that they are corrupted and disabled copies of genes. But with
all the new discoveries of uses for the ‘junk’, it is becoming increasingly
rash to claim that any DNA is ‘useless’.1
Geneticists at Saitama Medical School in Japan have now shown that a pseudogene
has a function. They genetically engineered mice to carry a fruit fly gene. The
mice were mostly OK, but some died in infancy when the fly gene was inserted into
a pseudogene, called Makorin1-p1.2
This shows that the pseudogene has a vital function (otherwise disabling it wouldn’t
have mattered), so is not junk at all. The pseudogene has such a similar sequence
to the gene, not because it is corrupted from it, but because it was designed that
way. The sequences must be highly similar because the pseudogene codes
for RNA that allows the ‘real’ gene to operate.3
This is a good lesson—just because we don’t know a function,
it is rash to claim that there is no function.
References and notes
- Sarfati, J., DNA: marvellous messages or mostly mess?
Creation 25(2):26–31, 2003.
- Mattick, J., cited in: Gibbs, W.W., The unseen genome: gems among the junk,
Scientific American 289(5):26–33, November 2003.
- This probably works because repressors that bind to the gene’s mRNA will also
bind to the pseudogene’s mRNA. Therefore the pseudogene mops up the repressors
so the gene is free to code for the protein. See Woodmorappe, J.,
Pseudogene function: more evidence, Journal of Creation 17(2):15–18,
2003.
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References and notes
- Sarfati, J., DNA: marvellous messages
or mostly mess? Creation 25(2):26–31, 2003.
Return to text.
- Mattick, J., cited in: Gibbs, W.W., The unseen
genome: gems among the junk, Scientific American 289(5):26–33,
November 2003. Return to text.
- However, more up-to-date information shows that long-distance
conduction is probably due to the surrounding water molecules rather than the DNA
itself—Biever, C., Electrifying claims dashed, New Scientist
177(2388):17, 29 March 2003. Return to text.
- Lawton, G., Live wire, New Scientist 177(2386):38–39,
15 March 2003. Return to text.
- Ananthaswamy, A., Enzymes scan DNA using electric pulse,
New Scientist 180(2417):10, 18 October 2003.
Return to text.
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