SPACI score report for 4exg in ASTRAL 2.04:

PDB Entry: 4exg
SPACI score: 0.49
AEROSPACI score: 0.49

Experiment type: XRAY
Resolution: 1.8
R-factor: 0.181
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -2.054
WCK2 WHAT_CHECK Ramachandran: -1.957
WCK3 WHAT_CHECK Chi angles: -1.289
WCK4 WHAT_CHECK Backbone: 1.158

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).