Initiation codon which is not ATG

Neil McEwan nrm at rri.sari.ac.uk
Thu Mar 25 10:17:23 EST 1999

Most molecular biological text books describe the universal start codon as
being ATG.  I am aware of a number of alternative start codons e.g.
described in some detail at the web page:


These include: TTA, TTG, CTG, ATT, ATC, ATA and GTG

Can anyone else supply evidence of additional initiation codons.  We have
found a few cDNA clones where alignments suggest that we have possibly found
the entire message, but where the initial anticipated Met would not be
encoded by one of the above.  Since we are working with a sequence from a
poorly studied protozoan, it is possible that many of the best sequences we
are comparing against our sequence are not going to be the same length as
the one we are working with.  However, even a histone sequence (with high
homology to other histone sequences) does not have any of the above codons
in a "sensible" position.

I have failed to add to the above list by doing literature searches, and so
any comments or additional information would be most welcome.

Thanks in advance for any replies

Dr Neil R. McEwan
Protein Metabolism Division
Rowett Research Institute
Greenburn Road
AB21 9SB
Tel. +44 (0)1224-712751
Fax. +44 (0)1224-715349

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