AtDRTSs gene structure and protein isoforms.

(A) Genomic organization of the AtDRTS gene paralogs and of the upstream AtSFH members. The exons are indicated as boxes with the UTR regions shown in gray and the coding portions in light blue. The portions corresponding to the DHFR and TS domains are indicated above the structure of the longest isoforms. The position of transposable elements is shown as dark red boxes below the gene structures. (B) Amino acid sequence comparison of the AtDRTS isoforms. The functional sites are indicated as described in the legend.