SPACI score report for 1usu in ASTRAL 1.71:

PDB Entry: 1usu
SPACI score: 0.37
AEROSPACI score: 0.37

Experiment type: XRAY
Resolution: 2.15
R-factor: 0.213
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: 0.194
WCK2 WHAT_CHECK Ramachandran: -1.436
WCK3 WHAT_CHECK Chi angles: -1.621
WCK4 WHAT_CHECK Backbone: -4.242

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).