TABLE 1.

Wild-type and φX174 ΔH^RV286L^a plating efficiencies in cells expressing N-terminal ΔH proteins

Expressed proteinc	Plating effiiciencyb
	Wild-type φX174	φX174 ΔHRV286L
None	1.0	1.0
ΔH142	<10−6	0.2
ΔH186	<10−6	0.1
ΔH238	10−2	0.6
ΔH277	10−2	1.2
ΔH299	1.2	1.1
ΔH142+Bd	0.05	1.0
ΔH142V286Le	0.4	1.0

^aA φX174 mutant resistant to the expression of ΔH proteins. The mutation confers a V→L substitution at amino acid 286.

^bPlating efficiency was determined as the titer on cells expressing ΔH proteins divided by the titer on cells expressing no exogenous proteins.

^cN-terminal H deletion proteins (ΔH): the number following ΔΗ is the number of amino acids deleted from the N terminus.

^dThe induced plasmid contains two genes, the ΔH142 gene immediately followed by the internal scaffolding protein B gene.

^eThe expressed protein contains the V286L mutation, which confers resistance to the expression of the ΔH proteins.