Posted by mara on Jun 04, 2002 at 15:05
(170.115.180.241)
Re: A Nobel Prize Has Been Earned ... I Suspect (damorgan)
i was looking at one of my biochemistry books and came across a paragraph entitled:
Cells Also Contain Nonstandard Amino Acids.
In addition to the 20 standard amino acids that are common in all proteins, other amino acids have been found as components of only certain kinds of proteins.
Among the non-standard amino acids are 4-hydroxyproline,....
5-hydroxylysine,...
N-methyllysine,...
gamma-carboxyglutamate,...
desmosine,...
and selenocysteine.
A second biochemistry book confirmed this statement. One book was copyrighted in 1983, the other in 1990.
These amino acids are suggested to be modifications of standard amino acids.
my question is: what was the 21st amino acid.
i'm not criticizing, i am asking. my idea is that the code itself is evolving.
also, if one looks at dna sequences in GenBank, there will be noted that there are other nucleotides besides; a, c, g, and t.
Re: Pyrrolysine DA Morgan 04/6 15:09
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