Pullulanases (pullulan 6-glucanohydrolase, EC 3.2.1.41) are debranching enzymes that are able to hydrolyze the alpha-1,6-glycosidic linkage in pullulan, starch, amylopectin, and related oligosaccharides. Type I pullulanases specifically cleave the al ...
Pullulanases (pullulan 6-glucanohydrolase, EC 3.2.1.41) are debranching enzymes that are able to hydrolyze the alpha-1,6-glycosidic linkage in pullulan, starch, amylopectin, and related oligosaccharides. Type I pullulanases specifically cleave the alpha-1,6-glycosidic linkages in pullulan and branched oligosaccharides to produce maltotriose and linear oligosaccharides, respectively [1]. Structural analysis of Klebsiella lipoprotein pullulanase (PulA) illustrates that the catalytic core is composed of two major regions: the TIM-barrel domain A and beta-sandwich fold domain C. PulA contains an extra domain, a highly mobile Ins subdomain of unknown function which is inserted into the catalytic TIM-barrel domain A of Klebsiella pullulanases. The Ins subdomain is rich in helical and loop secondary structure. A disulfide bond between Cys491 and Cys506 and two Ca2+ ions presumably stabilizes this domain.This insertion is also found in pullulanases from other Gram-negative genera that have a functional T2SS, such as Vibrio, Aeromonas, and Photorhabdus. Functional analysis indicate that this domain is required for PulA secretion via the T2SS [2].
This domain is found in a range of enzymes that act on branched substrates - isoamylase, pullulanase and branching enzyme. This family also contains the beta subunit of 5' AMP activated kinase.
Domain is found in pullanase - carbohydrate de-branching - proteins. It is found both to the N or the C terminii of of the alpha-amylase active site region. This domain contains several conserved aromatic residues that are suggestive of a carbohydrat ...
Domain is found in pullanase - carbohydrate de-branching - proteins. It is found both to the N or the C terminii of of the alpha-amylase active site region. This domain contains several conserved aromatic residues that are suggestive of a carbohydrate binding function.
This domain is found close to the N-terminus of the Klebsiella starch debranching pullulanase enzyme [1]. The structure of the domain is a beta sandwich fold.