SPACI score report for 1zka in ASTRAL 2.06:

PDB Entry: 1zka
SPACI score: 0.35
AEROSPACI score: 0.35

Experiment type: XRAY
Resolution: 2.2
R-factor: 0.206
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 3
WCK1 WHAT_CHECK Packing: -0.066
WCK2 WHAT_CHECK Ramachandran: -2.092
WCK3 WHAT_CHECK Chi angles: -3.02
WCK4 WHAT_CHECK Backbone: 0.874

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).