SPACI score report for 1sok in ASTRAL 2.04:

PDB Entry: 1sok
SPACI score: 0.55
AEROSPACI score: 0.55 (mutant; see below)

Experiment type: XRAY
Resolution: 1.6
R-factor: 0.225
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: 1.71
WCK2 WHAT_CHECK Ramachandran: -1.754
WCK3 WHAT_CHECK Chi angles: -0.772
WCK4 WHAT_CHECK Backbone: 3.371

The AEROSPACI score for this entry is lower than the SPACI score because human-curated comments on the entry in SCOPe contain the phrase mutant. The full comment is: "mutant"

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).