SPACI score report for 2y21 in ASTRAL 2.01:

PDB Entry: 2y21
SPACI score: 0.31
AEROSPACI score: 0.31

Experiment type: XRAY
Resolution: 2.45
R-factor: 0.24821
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 1
WCK1 WHAT_CHECK Packing: 0.618
WCK2 WHAT_CHECK Ramachandran: -1.248
WCK3 WHAT_CHECK Chi angles: -0.951
WCK4 WHAT_CHECK Backbone: 5.288

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).