[phenixbb] B-factor discrepancy

[Yuri]

I am refining a single-mutant structure at 2.1 A. The native was solved
years ago by heavy atom phasing. The reported average B-factors for
alpha carbons especially of the original structure were significantly
lower than the ones I am seeing.
around 15 vs. around 25.
Has anyone any idea if this is perfectly fine and its simply something
intrinsic to my crystals?
Also at this resolution, should I try to refine any residues at all
anisotropically?

Thanks for the guidance