TABLE 1.

Properties of the CAP mutants with mutations at the ara p_BAD promoter

CAP mutanta	No. of isolates	Activation at ara pBAD-I1-I1*b	Activation at ara pBAD-I1-I2c	Repression at placUV5-OCAPd
Wild type		5×	5×	7×
-CAP		1×	1×	1×
Leu-150→Pro	1	1.3×		4×
Ala-156→Gly	1	4×		5×
His-159→Pro	1	1.5×	1×	5×
Gly-162→Asp	3	2×		6×
Gly-162→Ser	2	1.5×		7×
Gln-164→Pro	1	2×		3×
Ser-46→Pro	1	2×		5×
Ile-51→Thr	1	1×	1×	6×
Lys-52→Glu	1	2×	3×	6×
Ile-60→Val	1	2×		6×
Leu-64→Pro	2	1.5×	2×	6×
Asp-68→Gly	1	2×	3×	6×
Asn-133→Asp	1	2×		6×

^aThe first group contains AR1 mutations. The second group has mutations clustered around the AR3 region. 

^bThe CAP activation was calculated by comparing ara p_BAD-I₁-I₁* promoter activity with and without a CAP binding site in the absence of arabinose in XE64.2 cells. 

^cThe CAP activation was calculated by comparing ara p_BAD-I₁-I₂ promoter activity with and without a CAP binding site in the presence of arabinose in XE64.2 cells. 

^dThe repression of the p_lacUV5-O^CAP promoter by CAP was determined in XE82 cells. In the absence and presence of wild-type CAP, the β-galactosidase expression of p_lacUV5-O^CAP is 40 and 280 U, respectively.