SPACI score report for 1zt4 in ASTRAL 2.03:

PDB Entry: 1zt4
SPACI score: 0.17
AEROSPACI score: 0.17

Experiment type: XRAY
Resolution: 3
R-factor: 0.234
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 3
PCK3 PROCHECK H-bonds: 3
WCK1 WHAT_CHECK Packing: -1.908
WCK2 WHAT_CHECK Ramachandran: -4.766
WCK3 WHAT_CHECK Chi angles: -4.167
WCK4 WHAT_CHECK Backbone: 1.692

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).