SPACI score report for 2a4x in ASTRAL 2.01:

PDB Entry: 2a4x
SPACI score: 0.61
AEROSPACI score: 0.61

Experiment type: XRAY
Resolution: 1.4
R-factor: 0.222
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -0.851
WCK2 WHAT_CHECK Ramachandran: -0.336
WCK3 WHAT_CHECK Chi angles: -2.678
WCK4 WHAT_CHECK Backbone: 1.053

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).