Figure 2

Comparison of gene structures of various thymidylate synthases. Exons are boxed and introns are shown as lines. The introns are annotated below the gene schemes with the number of codons they break within particular genes and with their phase, being 0 when falling between codons, and 1 or 2 when interrupting codons. Introns located in conserved or homologous positions, are marked with the same line pattern and the intron number within particular species gene. The positions of slide introns (5-nt slide in the case of Trichinella intron 1 vs. F. neoformans intron 1, and 3-nt slides in all other cases), are marked with asterisks. Exons are annotated with their numbers within particular genes and their phases given in the brackets. Number key within particular exon box indicates location of the enzyme active center. Dihydrofolate reductase (DHFR) and thymidylate synthase (TS) parts of bifunctional plant genes are marked below the gene schemes. Gene sequences that served for exon-intron junctions determination were obtained through the following accessions: Brugia malayi [GenBank:NW_001893010], Loa loa [GenBank:NW_003320690], Caenorhabditis elegans [GenBank:AF099673.1], Filobasidiella neoformans [GenBank:U12256.1], Pneumocystis carinii [GenBank:M25415.1], Rattus norvegicus [GenBank:NC_005108.3], Mus musculus [GenBank:NW_001030787.1], Homo sapiens GenBank:NC_000018.9], Bos Taurus [GenBank:GJ062838.1], Arabidopsis thaliana [GenBank:NC_003071.7], Daucus carota [GenBank:AJ003139.1]. Amino acid sequence alignment with marked intron positions is shown as Additional file1: Figure S3.