Fig. 1.

Phylogenetic relationship between Arabidopsis thaliana peptide transporter (PTR) proteins. Protein sequences representing 52 Arabidopsis PTR proteins (Pfam domain PF00854, TIGR release 5·0) were aligned by use of ClustalW (Chenna et al., 2003) with default alignment parameters. The region of the alignment corresponding to residues 55–585 of PTR2 was used for the generation of an unrooted phylogeny by parsimony analysis (phylogeny inference package; Felsenstein, 1998). Subfamilies I (19 members), III (14 members) and IV (10 members) are shaded whereas subfamily II (nine members) is left unshaded. The locations of CHL1 (AT1G12110), NTL1 (AT1G69850) and NTP2 (AT2G26690) in subfamily IV, PTR3 (AT5G46050) in subfamily III and PTR1 (AT3G54140) and PTR2 (AT2G02040) in subfamily II are indicated.