SPACI score report for 1b4p in ASTRAL 2.08:

WARNING! The SPACI score for this entry is not valid. The R-factor is not available and an abitrary R-factor has been used. The PROCHECK parameters for this entry could not be obtained, and poor results have been arbitrarily assumed.

PDB Entry: 1b4p
SPACI score: 0.4 (not valid)
AEROSPACI score: -1.6 (not valid) (chimer; see below)

Experiment type: XRAY
Resolution: 1.7
R-factor: 0.25
PCK1 PROCHECK Ramachandran: N/A
PCK2 PROCHECK Chi-1 angle: N/A
WCK1 WHAT_CHECK Packing: -1.344
WCK2 WHAT_CHECK Ramachandran: -1.92
WCK3 WHAT_CHECK Chi angles: -1.192
WCK4 WHAT_CHECK Backbone: 2.482

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: "chimeric isoenzyme; chimeric isozyme"

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).