FIG. 1.

Gene organization of the traA to -D and pilI to -V regions of pKK641-A′. The top horizontal line represents a restriction map. B, BglII; C, ClaI; E, EcoRI; H, HindIII; Hp, HpaI; P, PstI; S, SmaI; V, PvuII. Locations of insertion or deletion mutations and their transfer capacity are indicated (open circles, transfer proficient; solid circles, transfer deficient). Below the map, open reading frames are represented by arrows. tra, transfer; pil, formation of thin pilus; Shf, shufflon; rci, shufflon-specific recombinase. The solid lines on the bottom indicate DNA portions present in complementing plasmids.