FIG. 1.

TCRβ locus. (A) Gene segments are depicted as rectangles, the enhancer as a circle, and 12RSSs and 23RSSs as white and black triangles, respectively. The RSSs examined in this study are indicated. The map is not drawn to scale. (B) Relevant TCRβ locus RSS and coding flank sequences. The TCRβ RSSs are displayed below the consensus 12RSS and 23RSS sequences with differences from the consensus sequence indicated by lowercase letters. All coding flank residues are indicated with lowercase letters. Four conserved positions in the 5′Dβ spacers are underlined, and identities at these positions in the Jβ spacers are also indicated by underlining (see Discussion). The well-conserved, functionally important fifth spacer position is indicated by a black arrowhead. The RSS elements are numbered as indicated. The DNA substrates used in our experiments extend both 5′ and 3′ of the sequences shown here (Table 1).