FIG. 1.

(A) Restriction map of the 28-kb insert cloned in plasmid pMB374-07. The two lines above the restriction map represent subclones which showed the phenotypes indicated (SA⁻ and/or Pms⁻) when harbored by JM218. (B) Physical map of the minimal 5-kb EcoRI fragment responsible for SA biosynthesis. Lines below the restriction map represent different deletion clones and subclones constructed to delimit the minimal region involved in SA biosynthesis in E. coli. Production [(+)] or nonproduction [(−)] of SA is indicated. Restriction sites: E, EcoRI; B, BamHI; H, HindIII; S, SalI; Sc, SacI; Pv, PvuII; RV, EcoRV.