FIG. 3.

Organization of the trb region of pTiC58. Each arrow in the upper part of the figure represents the length of a single sequencing reaction. Relevant restriction sites are shown as vertical lines. Shaded arrows at the bottom represent the ORFs which are named after their RP4 homologues. The coordinates of the start and stop codons of each ORF are with respect to the BglII cleavage site in the region just upstream of traI as position 1. The arrow labeled P just before traI represents the location of the traI/trb promoter. The level of each ORF arrow indicates its reading frame.