Amylo-alpha-1,6-glucosidase. This family includes human glycogen branching enzyme AGL. This enzyme contains a number of distinct catalytic activities. It has been shown for the yeast homolog GDB1 that mutations in this region disrupt the enzymes Amylo-alpha-1,6-glucosidase (EC:3.2.1.33).
glycogen debranching enzyme, archaeal type, putative. The seed for this model is composed of two uncharacterized archaeal proteins from Methanosarcina acetivorans and Sulfolobus solfataricus. Trusted cutoff is set so that essentially only archaeal members hit the model. The notable exceptions to archaeal membership are the Gram positive Clostridium perfringens which scores much better than some other archaea and the Cyanobacterium Nostoc sp. which scores just above the trusted cutoff. Noise cutoff is set to exclude the characterized eukaryotic glycogen debranching enzyme in S. cerevisiae. These cutoffs leave the prokaryotes Porphyromonas gingivalis and Deinococcus radiodurans below trusted but above noise. Multiple alignments including these last two species exhibit sequence divergence which may suggest a subtly different function for these prokaryotic proteins. [Energy metabolism, Biosynthesis and degradation of polysaccharides]
glycogen debranching enzymye. glycogen debranching enzyme possesses two different catalytic activities; oligo-1,4-->1,4-glucantransferase (EC 2.4.1.25) and amylo-1,6-glucosidase (EC 3.2.1.33). Site directed mutagenesis studies in S. cerevisiae indicate that the transferase and glucosidase activities are independent and located in different regions of the polypeptide chain. Proteins in this model belong to the larger alpha-amylase family. The model covers eukaryotic proteins with a seed composed of human, nematode and yeast sequences. Yeast seed sequence is well characterized. The model is quite rigorous; either query sequence yields large bit score or it fails to hit the model altogether. There doesn't appear to be any middle ground. [Energy metabolism, Biosynthesis and degradation of polysaccharides]
Glycosyl-hydrolase family 116, catalytic region. This represents a family of archaeal, bacterial and eukaryotic glycosyl hydrolases, that belong to superfamily GH116. The primary catabolic pathway for glucosylceramide is catalysis by the lysosomal enzyme glucocerebrosidase. In higher eukaryotes, glucosylceramide is the precursor of glycosphingolipids, a complex group of ubiquitous membrane lipids. Mutations in the human protein cause motor-neurone defects in hereditary spastic paraplegia. The catalytic nucleophile, identified in UniProtKB:Q97YG8_SULSO, is a glutamine-335, with the likely acid/base at Asp-442 and the aspartates at Asp-406 and Asp-458 residues also playing a role in the catalysis of glucosides and xylosides that are beta-bound to hydrophobic groups. The family is defined as GH116, which presently includes enzymes with beta-glucosidase, EC:3.2.1.21, beta-xylosidase, EC:3.2.1.37, and glucocerebrosidase EC:3.2.1.45 activity.