Abstract.
The available amino acid sequences of the α-amylase family (glycosyl hydrolase family 13) were searched to identify their domain B, a distinct domain that protrudes from the regular catalytic (β/α)8-barrel between the strand β3 and the helix α3. The isolated domain B sequences were inspected visually and also analyzed by Hydrophobic Cluster Analysis (HCA) to find common features. Sequence analyses and inspection of the few available three-dimensional structures suggest that the secondary structure of domain B varies with the enzyme specificity. Domain B in these different forms, however, may still have evolved from a common ancestor. The largest number of different specificities was found in the group with structural similarity to domain B from Bacillus cereus oligo-1,6-glucosidase that contains an α-helix succeeded by a three-stranded antiparallel β-sheet. These enzymes are α-glucosidase, cyclomaltodextrinase, dextran glucosidase, trehalose-6-phosphate hydrolase, neopullulanase, and a few α-amylases. Domain B of this type was observed also in some mammalian proteins involved in the transport of amino acids. These proteins show remarkable similarity with (β/α)8-barrel elements throughout the entire sequence of enzymes from the oligo-1,6-glucosidase group. The transport proteins, in turn, resemble the animal 4F2 heavy-chain cell surface antigens, for which the sequences either lack domain B or contain only parts thereof. The similarities are compiled to indicate a possible route of domain evolution in the α-amylase family.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Author information
Authors and Affiliations
Additional information
Received: 4 December 1996 / Accepted: 13 March 1997
Rights and permissions
About this article
Cite this article
Janecek, S., Svensson, B. & Henrissat, B. Domain Evolution in the α-Amylase Family. J Mol Evol 45, 322–331 (1997). https://doi.org/10.1007/PL00006236
Issue Date:
DOI: https://doi.org/10.1007/PL00006236