FIG. 1.

Physical map of a cloned fragment containing the orfX, orf1, and bexA (orf2) genes from B. thetaiotaomicron. Although a 5.3-kb DNA fragment partially digested with Sau3A was cloned into the BamHI site of pBR322, the right side of the insert-vector junction remained cleavable with BamHI. The arrows at the bottom indicate putative open reading frames and their directions of transcription. Arrowheads indicate the approximate positions and the directions of transcription of the tet promoter in the vector pBR322.