SPACI score report for 1s3k in ASTRAL 2.03:

PDB Entry: 1s3k
SPACI score: 0.47
AEROSPACI score: -1.53 (chimer; see below)

Experiment type: XRAY
Resolution: 1.9
R-factor: 0.203
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: 0.105
WCK2 WHAT_CHECK Ramachandran: -1.545
WCK3 WHAT_CHECK Chi angles: -1.789
WCK4 WHAT_CHECK Backbone: 2.87

The AEROSPACI score for this entry is lower than the SPACI score because human-curated comments on the entry in SCOPe contain the phrase chimer. The full comment is: "MQ NA P01857 # artificial chimera; MQ NA # artificial chimera"

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).