Figure 2
The conserved ancestral core module: Multiple alignment. The sequences are described to the left by their NR accession followed by the species name and an upper-case letter representing the annotated substrate specificity (A for lipases, B for esterases in general, C for phospholipases, D for lysophospholipases, E for a Brefeldin A esterase, F for acetyl xylan esterases, G for dienelactone hydrolases, X for unknown). The alignment includes the path sequences from figure 1 (marked by red asterisk between parentheses (*) in front of the accessions) in addition to proteins from most major clusters. Sequences with resolved crystal structures are shown with a lower-case letter between parentheses to the left. The corresponding PDB accessions are (a) 4TGL [22], (b) 1JKM [23], (c) 1TCB [24], (d) 1EX9 [25], (e) 1KU0 [26], (f) 1N8S [27], (g) 1VLQ (unpublished), (h) 1DIN [28], (i) 1AUO [29], (j) 1FJ2 [30], (k) 1M33 [31], (l) 1OXW [13] and (m) 1CJY [14]. The upper part of the sequence description with the blue background shows proteins from the classic α/β-hydrolase fold family, the lower part with the red background shows sequences from the ATGL/patatin group. The alignment to the right shows the secondary structural elements from the core module: the β-strands β-2, β-1, β+1 and the α-helix α+1. These helices and sheets are depicted above in their typical lengths as judged from the included 3D structures. Central part of the alignment is the nucleophilic elbow with the archetypical GXSXG sequence. The location of the nucleophilic residue (mainly serine, but two dienelactone hydrolases with active cysteines are also shown) is indicated by a blue triangle on top of the alignment. The numbers that flank the alignment show the start and end positions of the displayed subsequences with regard to the corresponding entries. The numbers in brackets between the secondary structural elements represent amino acids that are not shown in the alignment.