[ssml] Unusual amino-acid composition ?

[Gerard DVD Kleywegt]

hi all,

we are writing up the structure determination of a dimeric human enzyme. while 
going through the model (~750 residues per monomer), i noticed that the 
protein contains rather few lysines (1.8%) and isoleucines (2.7%), and rather 
many prolines (7.5%) and phenylalanines (6.5%). (if i remember correctly, 
there are no low-complexity regions in the sequence.)

i would be grateful for any clues or literature references that might tell us 
if this is statistically to be expected or unusual and -if the latter- what 
could explain it, and whether or not it might have any significance. also, a 
pointer to a table of the average amino-acid composition of soluble human 
proteins (or enzymes) would be useful.

thanks in advance for any input !

--gerard

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                         Gerard J.  Kleywegt
     [Research Fellow of the Royal  Swedish Academy of Sciences]
Dept. of Cell & Molecular Biology  University of Uppsala
                 Biomedical Centre  Box 596
                 SE-751 24 Uppsala  SWEDEN

     http://xray.bmc.uu.se/gerard/  mailto:gerard at xray.bmc.uu.se
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