SPACI score report for 2ykb in ASTRAL 2.07:

PDB Entry: 2ykb
SPACI score: 0.44
AEROSPACI score: 0.44

Experiment type: XRAY
Resolution: 1.93
R-factor: 0.2015
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -1.208
WCK2 WHAT_CHECK Ramachandran: -1.062
WCK3 WHAT_CHECK Chi angles: -1.01
WCK4 WHAT_CHECK Backbone: -1.025

Note: Here are links to pages about PROCHECK and WHAT_CHECK.

Here is the full WHAT_CHECK report on this protein (linked from the WHAT_CHECK site).