SPACI score report for 2c28 in ASTRAL 2.08:

PDB Entry: 2c28
SPACI score: 0.34
AEROSPACI score: 0.34

Experiment type: XRAY
Resolution: 2.27
R-factor: 0.239
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -0.43
WCK2 WHAT_CHECK Ramachandran: -1.593
WCK3 WHAT_CHECK Chi angles: -1.351
WCK4 WHAT_CHECK Backbone: -0.576

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).