DNA repair

Iuval cCejan clejan at mindspring.com
Tue Dec 19 12:07:28 EST 2000

"Dr. Sydney Shall" wrote:

> > 2. Are there any studies of how the nuclear genes coding for mtDNA
> > repair enzymes are themselves repaired? One can imagine a stable system
> > (biological or cybernetic) in which all repair mechanisms can also
> > repair each other (it's stable because it would take SIMULTANEOUS damage
> > to all repair mechanisms to destabilize it, which is unlikely), but if
> > the nodes of this system are not all connected  to each other (i.e.
> > repairing each other) and there is an achiles heel node that is least
> > connected, the system would become unstable over time and might exhibit
> > some of the characteristics of ageing. Is pol gamma the only repair
> > enzyme for mtDNA? Does the nuc gene encoding it get repaired by anything
> > else?
> >
> This is an interesting point.  Clearly the GENES coding for the repair
> proteins are repaired by these proteins.  This is OK, however because they
> can stop making proteins temporarily with safety

But this is unstable because if a gene codes for its own repair protein, a
mutation of the gene is likely to either stop coding for anything or code for
a protein which is ineffectual in repairing. Why can the protein fabrication be

stopped with safety? If there are other (essential) genes that need to be
repaired by this protein those genes will be fubared as well, unless they have
alternative repair proteins.


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