SPACI score report for 1z06 in ASTRAL 2.07:

PDB Entry: 1z06
SPACI score: 0.51
AEROSPACI score: 0.51

Experiment type: XRAY
Resolution: 1.81
R-factor: 0.191
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -1.507
WCK2 WHAT_CHECK Ramachandran: -0.259
WCK3 WHAT_CHECK Chi angles: 0.061
WCK4 WHAT_CHECK Backbone: 0.003

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).