Multiple sequence alignment. (A) Multiple sequence alignment of A. niger K10 with template structures 1EMS , 1J31 , 1F89 , 2VHH  and 2W1V  (letters in upper case) and sequences of homologous nitrilases (letters in lower case) from Rhodococcus rhodochrous J1 (RrJ1)  and from Pseudomonas fluorescens (Pf-5) . Clustal W scheme is used for marking similar residues. Amino acids from catalytic triad are strongly conserved; they are marked by red arrow and enclosed in blue rectangles. Secondary structures for template 1EMS and A. niger K 10 nitrilase model are shown above and under the aligned sequences, respectively, with numeration as in . (B) Sequence alignment of A. niger K 10 with 2KIN  was used for modelling the C-terminal part. Secondary structure as assigned by Procheck  is shown for A. niger K 10 and for 2KIN above and under the aligned sequences, respectively.