PMC

Representation of the putative platypus venom gene families discovered by homology searching with other toxin sequences. Putative functions are shown in Table 1.

Unrooted neighbor-joining phylogenetic tree of the kunitz domain-containing putative platypus venom peptides (boxed). Bootstrap values less than 50 have been omitted. ENSOANT represents platypus homologues not expressed in venom gland.

Gene Ontology annotation of putative platypus venom genes. (a) Biological process; (b) cellular component; (c) molecular function. Data can be classified under more than one GO term.

Representation of domain order in the platypus venom metalloproteinases for which we appear to have complete sequence. Lowercase h denotes that the residue is not found in all platypus sequences. This arrangement mirrors that of the snake venom PIII metalloproteinases (after Matsui et al. []). Domains were identified using BLAST searches of the NCBI Conserved Domains database [].

Partial MUSCLE alignment of putative platypus venom kallikrein serine protease sequences, showing the most conserved regions. The full alignment can be seen in Figure S5 in Additional file . Gilatoxin (P43685), blarina toxin (BAD18893), blarinasin (Q5FBW2), two snake sequences and two human tissue kallikreins are also shown (SWISS-PROT accession numbers are listed). The catalytic triad is highlighted in pink, and conserved cysteines highlighted in blue. Not all platypus venom peptides contain the triad and cysteines.