TABLE 3.

The Mx8 int gene has two alternate start codons^a

Plasmid	Genotype	Avg EOE (103 μg−1) ± SD	Phenotype
pAY721	Wild type	2.1 ± 1.2	Int+
pAY979	intVA1	1.0 ± 0.8	Int+
pAY754	intVA42	0.5 ± 0.4	Int+
pAY990	intVA1VA42	<0.001	Int−

^aPlasmid pAY721 with the wild-type int gene or its otherwise isogenic derivatives with each or both changes of potential GTG-5085 and GTG-5208 start codons to GCG, VA1, and VA42, respectively, were electroporated into host DZ1. The efficiency of electroporation (EOE) is the frequency of Km^r electroporants per microgram of plasmid DNA; values are the averages of four independent experiments. The double-mutant plasmid fails to integrate.