SPACI score report for 1yk4 in ASTRAL 2.03:

PDB Entry: 1yk4
SPACI score: 1.51
AEROSPACI score: 1.51

Experiment type: XRAY
Resolution: 0.69
R-factor: 0.1
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: 0.5
WCK2 WHAT_CHECK Ramachandran: 0.667
WCK3 WHAT_CHECK Chi angles: 1.256
WCK4 WHAT_CHECK Backbone: 1.855

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).