Asp-Tyr H bonds

[John Rathjen]

Hi All:
I wonder if anyone could suggest an answer(s) to my problem.  I have a
tyrosine residue in a protein sequence which I suspect is phosphorylated.
I want to mutate it to stop the (putative) phosphorylation event.  The
problem is that I believe the Tyr residue is hydrogen bonded to an Asp
residue, and that this interaction is important for binding of another
protein which binds prior to phosphorylation.  So my question is, which
residues can I mutate the Tyr to which would have best chance of retaining
the interaction with the Asp residue?
Thanks for your help!
John

John Rathjen 
CEPRAP, UC Davis