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From: howard@cpocd2.UUCP
Newsgroups: sci.bio
Subject: Re: information content of DNA
Message-ID: <569@cpocd2.UUCP>
Date: Thu, 9-Apr-87 17:33:45 EST
Article-I.D.: cpocd2.569
Posted: Thu Apr  9 17:33:45 1987
Date-Received: Sat, 11-Apr-87 15:13:59 EST
References: <2840@ecsvax.UUCP> <11189@teknowledge-vaxc.ARPA> <978@aecom.UUCP> <425@haddock.UUCP> <1010@aecom.UUCP> <430@haddock.UUCP> <891@s9 Apr 87 22:33:45 GMT
Reply-To: howard@cpocd2.UUCP (Howard A. Landman)
Organization: Intel Corp. ASIC Services Organization, Chandler AZ
Lines: 25

In article <891@sigi.Colorado.EDU> eddy@beagle.Colorado.EDU (Sean Eddy) writes:
>No, John, the point Dizzy was making was that while cases of overlap exist,
>they are 1)very rare  2)very short and 3)only in two of the three reading
>frames.

I'm sure there was an article in Sci Am recently about a virus which had a
very short segment of triple overlap.  This makes point 3 false.

>And remember that your original point was that any given sequence 
>potentially represents 6 (!) codings, not just two. Dizzy rightly
>replied that this is a good approximation to impossible. 

Any sequence not containing a terminator does, in some sense, code for 6
proteins.  It would perhaps be more accurate to say that the probability of
all 6 of these proteins being at all functional (or, less likely, actually
produced by an organism) is very close to zero.  The exact probability
is a negative exponential of the sequence length, which we could approximate
via information theory and statistics about protein mutability vs. function.
Anyone have any relevant statistics?
-- 
Copyright (c) 1987 by Howard A. Landman.  You may copy this material for any
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