Analysis of ML domain containing proteins. (A) Phylogenetic tree based on maximum likelihood analysis of a Dermacentor variabilis midgut protein and published ML domain protein sequences. The transcripts identified in this analysis are in bold (DvM). Phylogenetic analysis was conducted on protein alignments using Tree Puzzle version 5.2. Values at nodes represent calculated internal branch node support (1000 replications). (B) Multiple sequence alignment (CLUSTALX) of protein sequences identified in a cDNA library of unfed/2 d fed or 6 d fed D. variabilis midguts (DvM) and published sequences found on Genbank. The conserved cysteines are highlighted. Number signs (#) represents putative cholesterol/lipid binding site sites based on the conserved domain of Niemann-Pick type C2 (Npc2) proteins (italisized). Asterisks (*) indicated amino acids involved in the putative lipid binding cavity based on ML domain of the dust mite allergen, Der P 2 (bold). Shading represents 100% identity (black) or similarity (grey) among the sequences. Alignments were conducted using CLUSTALX. D. variabilis (Dv), Ixodes ricinus (Ir), Acarus siro (As), Schistosoma japonicum (Sj), Dermatophagoides pteronyssius (Dp), Ornithodoros parkeri (Op), Tyrophagus putrescentiae (Tp), Bos Taurus (Bt).