Friday, November 20, 2009

crystallography resolution (in Angstroems)

Some rules of thumb for 'outsiders'

Resolution Meaning:
>4.0 Coordinates meaningless
3.0 - 4.0 Fold possibly correct, but errors are
very likely. Many sidechains placed
with wrong rotamer.
2.5 - 3.0 Fold likely correct except that some surface
loops might be mismodelled. Several long, thin
sidechains (lys, glu, gln, etc) and small
sidechains (ser, val, thr, etc) likely to
have wrong rotamers.
2.0 - 2.5 As 2.5 - 3.0, but number of sidechains in
wrong rotamer is considerably less. Many
small errors can normally be detected.
Fold normally correct and number of errors
in surface loops is small.
1.5 - 2.0 Few residues have wrong rotamer. Many
small errors can normally be detected.
Fold always correct, also in surface loops.
0.5 - 1.5 One must be a determined idiot to screw
things up at this resolution, but don't
be fooled, even at this resolution can
we find threonines with the wrong chrirality
on the C-beta. But in general, structures
have only some small errors at this

i can see that my 0.9A structure contrains me to be as awaken as possible to avoid to get the "determined idiot"
nickname ....

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