TABLE 4.

Evaluation of a one-site versus a two-site model

Protein	Akaike information criteriona
	2-site model	1-site model
H2B	NA	−3.82
H10	−2.8	−2.74
HMGB1	NA	−2.94
HMGN1	−3.23	−3.02
HP1β	−4.1	−3.28
BRG1	−3.16	−2.85
PCAF	−3.04	−2.74
AhR	−2.56	−2.30
ARNT	−3.56	−3.27
C/EBP	−3.54	−3.08
NF1	−3.11	−2.84
Jun	−3.87	−3.29
Fos	−2.77	−2.55
Myc	−2.71	−2.54
Max	−3.20	−2.95
Mad	−3.17	−2.54
FBP	NA	−3.31
XBP	−3.09	−2.43
BRD4	−3.44	−2.89

^aExperimental data were fitted to either a one or a two-site binding model. A variant of the Akaike information criterion (AIC) was used to identify the best model for each protein (2). The AIC is a function of the objective function used by the parameter estimation routine in SAAM II, the number of adjustable parameters, and the number of data points. This function penalizes an improvement in the residual sum of squares whenever additional parameters are added to the model. The model with the minimum AIC is always preferred. The lower value is in boldface. With the exception of H2B, HMGB1, and FBP, all experimental data fit more accurately a two-site model than a one-site model. NA, not applicable.