title: The type II pullulanase of Thermococcus hydrothermalis: molecular characterization of the gene and expression of the catalytic domain.
abstract: The gene encoding a hyperthermostable type II pullulanase produced by Thermococcus hydrothermalis (Th-Apu) has been isolated. Analysis of a total of 5.2 kb of genomic DNA has revealed the presence of three open reading frames, one of which (apuA) encodes the pullulanase. This enzyme is composed of 1,339 amino acid residues and exhibits a multidomain structure. In addition to a typical N-terminal signal peptide, Th-Apu possesses a catalytic domain, a domain bearing S-layer homology-like motifs, a Thr-rich region, and a potential C-terminal transmembrane domain. The presence of these noncatalytic domains suggests that Th-Apu may be anchored to the cell surface and be O glycosylated.
mesh_terms: D000595:Amino Acid Sequence; D020134:Catalytic Domain / Q000235:genetics; D016386:Chromosome Walking; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D019766:Genes, Archaeal; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D006031:Glycosylation; D007527:Isoenzymes / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016366:Open Reading Frames / Q000235:genetics; D009876:Operon / Q000235:genetics; D021382:Protein Sorting Signals / Q000737:chemistry / Q000235:genetics; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification; D016415:Sequence Alignment; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D019712:Thermococcus / Q000201:enzymology* / Q000235:genetics