SPACI score report for 1zk2 in ASTRAL 2.08:

PDB Entry: 1zk2
SPACI score: 0.66
AEROSPACI score: 0.66

Experiment type: XRAY
Resolution: 1.55
R-factor: 0.149
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 1
WCK1 WHAT_CHECK Packing: 0.371
WCK2 WHAT_CHECK Ramachandran: -1.387
WCK3 WHAT_CHECK Chi angles: -0.685
WCK4 WHAT_CHECK Backbone: 4.182

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).