Dear Crystallographers (and cryo-EM practitioners,)
I do not understand why there is a discrepancy between what crystallographers
use to models disordered regions (b-factors/occupancies) and what the cryo-EM
world uses ("local resolution.") I am tempted to say that "local resolution" is
a misnomer, since I have been trained to think of resolution as a simple
optical or physical characteristic of the experiment, and things that are
blurry can in fact be "resolved" while disordered-one might think of the
blurred wings of an insect in a long-exposure photograph, in which the
resolution is of course ample to see the wings-but is there a good reason why
the two different terms/concepts are used in the different fields? Could
crystallographers learn from or appropriate the concept of local resolution to
good benefit, or perhaps vice versa? Anyway, if there is a good reason for the
discrepancy, fine, but otherwise, having these different measures prevents
straightforward comparisons which would otherwise be helpful.
All the best,
Jacob Keller
