An alignment of ascomycete and basidiomycete PRP8 inteins. Similar residue types have the same colour background. Accession numbers for the PRP8 intein sequences are in Table 1. The box diagram at the base of the alignment indicates the general shape of the largest inteins in the alignment. The arrangement of the splicing domains (blocks A, B, F and G) and endonuclease domains (blocks C, D, E and H) are indicated.