>monty at watson.open.ac.uk (Tony Hirst) writes:
> Another novice question....
>> the complementary strands of DNA, when trnascribed between two points, will
> translate to two different sequences depending on which strand of the helix
> is transcribed.
>> Qn: are the decoded complementary sequences both necessarily 'useful' (i.e.
> not nonsensical) or does DNA employ complementarity solely to facilatate
> replication and repair?
Both strands can yield functional proteins... I think a good example would be viral DNA which
can have different functional proteins encoded by the same DNA but in different reading frames in
on either strand for a given section of DNA ( Adeno-2 for example). This is probably because
of constraints on size of the virus' genome. In mammalian cells you have the Rag-1 and Rag-2
genes (responsible for VDJ recombinase activity) that are convergently transcribed... for this reason
they are hypothesized to have been derived from a fungal transposable element many eons ago.
The obverse of this is that as well as multiple
- coding over a single sequence through frameshifts, multiple coding is
- achieved through DNA's dual-strand nature.....
-
- Rep[ies via email preferably, or to the CSTB list
- (Majordomo at biome.bio.ns.cs)...
>> thanks in advance
>> tony hirst
>> ps - replies to my previously posted 'genetic code & mutation rates' are
> still sought after..
>> --------------------------------------------------------------------------
> All opinions etc etc...
> --------------------------------------------------------------------------
> | Tony Hirst ("Monty") | e-mail: A.J.Hirst at open.ac.uk> -------------------------------------------------------------------
> | "There is no meaning..." "Science is a subset of art..."
> -------------------------------------------------------------------
>>>>>
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