Fig. 2. Putative FK506-binding proteins FKB1_SUBDO and FKB2_SUBDO. (A) Alignment of the deduced sponge sequences, (FKB1_SUBDO and FKB2_SUBDO) with the human FK506-binding protein (FKB_HOMO; GenBank accession number NP_004107). Residues conserved (identical or similar with respect to their physico-chemical properties) in all sequences are shown in white on black and those in at least two sequences in black on gray. The locations of the two FKBP-type peptidyl-prolyl cis–trans isomerase signatures 1 and 2 (FKBP-1 and FKBP-2) are marked. In addition, the transmembrane helix (TM) is indicated in FKB2_SUBDO. (B) Rooted phylogenetic tree built by two listed sequences (FKB1_SUBDO and FKB_HOMO; Homo) as well as by the related sequences from Manduca sexta (Manduca; AAF16717), Xenopus laevis (Xenopus; O42123), Saccharomyces cerevisiae (Saccharomyces; NP_014264) and Arabidopsis thaliana (Arabidopsis; S72485). The last sequence was used as an outgroup. Scale bar indicates an evolutionary distance of 0.1 amino acid substitutions per position in the sequence.