Oligo-1,6-glucosidase and neopullulanase enzyme subfamilies from the alpha-amylase family defined by the fifth conserved sequence region.
The alpha-amylase enzyme family is the largest family of glycoside hydrolases. It contains almost 30 different enzyme specificities covering hydrolases, transferases and isomerases. Some of the enzyme specificities from the family are closely related, others less so. This study, based on the analysis of 79 amino acid sequences, postulates two subfamilies in the framework of the aamylase family: the oligo-1,6-glucosidase subfamily and the neopullulanase subfamily. The specific sequence in the fifth conserved sequence region of the family served as the basis for defining the subfamilies: QpDln for the oligo-1,6-glucosidase subfamily and MPKln for the neopullulanase subfamily. This conserved sequence region is proposed to be the selection marker that enables one to distinguish between the two subfamilies. The 'intermediary' sequence MPDLN can be characteristic of the so-called intermediary group with a mixed enzyme specificity of alpha-amylase, cyclomaltodextrinase and neopullulanase. The evolutionary trees clearly supported the proposed definition of the two subfamilies.
Oslancová
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Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 84251 Bratislava, Slovakia.
Janecek
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D000595:Amino Acid Sequence; D000818:Animals; D001419:Bacteria / Q000201:enzymology; D017124:Conserved Sequence; D019143:Evolution, Molecular; D005656:Fungal Proteins / Q000502:physiology; D005658:Fungi / Q000201:enzymology; D006026:Glycoside Hydrolases / Q000145:classification / Q000235:genetics*; D005810:Multigene Family; D009834:Oligo-1,6-Glucosidase / Q000145:classification / Q000235:genetics*; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D000516:alpha-Amylases / Q000145:classification / Q000235:genetics*
D005656:Fungal Proteins; D006026:Glycoside Hydrolases; D000516:alpha-Amylases; D009834:Oligo-1,6-Glucosidase; C058484:neopullulanase