On 16 Feb 2000, Mina wrote:
> Recently, I found a consensus sequence described as : psi - K - X - E.
> Can somebody tell me which amino acids belong to "psi", what
> classification is that or just point me to a reference.
one possibility is that psi stands for pseudo - i.e. it means that the
amino acids may be a pseudo-amino acid such as pseudo-proline or
whatever residue that is unnatural or unusual. For example, the CO
or NH group may be replaced by CH2 group so that the peptide bond
becomes non-hydrolysable, or the side-chains has other atoms or groups
attached or replaced.