Structure of inserts conferring antibiotic resistance in the organic swine fecal metagenomic library. ORFs are represented by arrows. The shaded arrows within clone 3 indicate the area identical to the sequence of clone 7. The DNA %G+C content is shown above the ORFs, and the percentage of similarity to database entries (where appropriate) is in brackets below the ORFs. Conserved regions are marked with: *, 158-bp region downstream of tet(40); **, 350 bp within the core 657-bp region upstream of tet(W); ***, 95-bp region downstream of tet(W) as in A. pyogenes; ****, 657-bp core region upstream of tet(W).