FIG. 4.

Genetic map of the p-vac region and strategy for the construction of the minvac region. The 14 gvp genes of the p-vac region are represented by boxes labeled A and C through O. Essential gvp genes are represented by grey boxes, and nonessential genes are represented by white boxes. Arrows indicate the locations of the endogenous promoters. Restriction sites used to obtain p-vac subfragments 1 to 3, used for the construction of the minvac plasmid, are shown at the top as follows: A, Asp718; B, BglII; E, EcoRI; H, HindIII; P, PshAI; RV, EcoRV; S, ScaI. The respective subfragments are shown as bars. For further explanations, see Materials and Methods. The minvac construct at the bottom acquired deletions of gvpDE, gvpHI, and gvpCN. ISH2, halobacterial insertion element.