SPACI score report for 3a4z in ASTRAL 2.03:

PDB Entry: 3a4z
SPACI score: 0.37
AEROSPACI score: 0.37

Experiment type: XRAY
Resolution: 2.2
R-factor: 0.203
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -0.747
WCK2 WHAT_CHECK Ramachandran: -1.996
WCK3 WHAT_CHECK Chi angles: -1.542
WCK4 WHAT_CHECK Backbone: -0.505

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).