Table 2.

Characteristics of the three mutant classes

Strain	Alkaline phosphatase activity*	ompA†	Motility	Cu2+ resistance‡	DsbC dependence§	Locus	No. of mutants
Wild type	159.3  ± 12.4	+	++++	+
dsbA::kan	4  ± 1.8	+	—	+
Class I	7.9  ± 1.6	+	+	—	Yes	dipZ−	5
Class II	22.2  ± 4.9	—	+++	—	Yes	dipZ−	2
Class III	10.5  ± 4.9	+	+	−/+	Yes	trxA−	1
Class II/dsbC−	2.2  ± 1.6		—
Class III/dsbC−	Not assayed		—

^*Phosphatase assays were performed as described in Materials and Methods on strains carrying the phoA68 signal sequence mutation. 

^†Indicates whether or not the strains contain an intact ompA gene. 

^‡Cu²⁺ resistance refers to the ability of the strain to grow in the presence of 4 mM cupric sulfate. 

^§DsbC dependence indicates whether suppression depends on the presence of a functional dsbC allele.