googling "dityrosine" suggests thaey can be formed by osidation by Cu or Ni
ions.
In structures of cytochrome oxidase, Tyrosine forms a covalent bond
from the same meta carbon to NE2 of a histidine. see Fig 1 of:
http://www.sciencemag.org/content/280/5370/1723.long
And histidine is ligating a Cu.
It is believed to be functionally relevant.
James Stroud wrote:
The hydroxyls were on the wrong carbons in the previous picture I sent. These
are correct.
James
On Jul 11, 2012, at 1:37 PM, Lukacs, Christine wrote:
Hi all-
I have a protein that crystallizes in I422, and diffracts well, between
1.3-1.7A.
Beautiful density, slightly higher final R-factors than you might expect at this
resolution (low to mid 20s). The density is all beautiful, except that I have
this one
little clash, between a few atoms from a tyrosine and its symmetry mate. In
this picture
I have it modeled as an Alanine and you can see the two tyrosine rings
interlocking; and
there is clearly no alternate conformation.
<image003.png>
Since it is not near my site of interest, I have been pretty much ignoring it,
going
through refinement with it as an alanine, then changing it at the very end to a
tyrosine
and just minimizing B-s, no positional. Now that I plan to publish a bunch of
these, I
should probably figure out what is really going on. Any insights?
Thanks
Christine
*Christine Lukacs*
Roche
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