Summary: Alpha amylase, C-terminal all-beta domain
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Alpha amylase, C-terminal all-beta domain Provide feedback
Alpha amylase is classified as family 13 of the glycosyl hydrolases. The structure is an 8 stranded alpha/beta barrel containing the active site, interrupted by a ~70 a.a. calcium-binding domain protruding between beta strand 3 and alpha helix 3, and a carboxyl-terminal Greek key beta-barrel domain.
Literature references
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Larson SB, Greenwood A, Cascio D, Day J, McPherson A; , J Mol Biol 1994;235:1560-1584.: Refined molecular structure of pig pancreatic alpha-amylase at 2.1 A resolution. PUBMED:8107092 EPMC:8107092
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Strobl S, Maskos K, Betz M, Wiegand G, Huber R, Gomis-Ruth FX, Glockshuber R; , J Mol Biol 1998;278:617-628.: Crystal structure of yellow meal worm alpha-amylase at 1.64 A resolution. PUBMED:9600843 EPMC:9600843
Internal database links
SCOOP: | Alpha-amy_C_pro DUF3459 Malt_amylase_C |
Similarity to PfamA using HHSearch: | Cyc-maltodext_C Malt_amylase_C |
External database links
PRINTS: | PR00110 |
SCOP: | 1ppi |
This tab holds annotation information from the InterPro database.
InterPro entry IPR006048
Alpha-amylase is classified as family 13 of the glycosyl hydrolases and is present in archaea, bacteria, plants and animals. Alpha-amylase is an essential enzyme in alpha-glucan metabolism, acting to catalyse the hydrolysis of alpha-1,4-glucosidic bonds of glycogen, starch and related polysaccharides. Although all alpha-amylases possess the same catalytic function, they can vary with respect to sequence. In general, they are composed of three domains: a TIM barrel containing the active site residues and chloride ion-binding site (domain A), a long loop region inserted between the third beta strand and the alpha-helix of domain A that contains calcium-binding site(s) (domain B), and a C-terminal beta-sheet domain that appears to show some variability in sequence and length between amylases (domain C) [ PUBMED:11141191 ]. Amylases have at least one conserved calcium-binding site, as calcium is essential for the stability of the enzyme. The chloride-binding functions to activate the enzyme, which acts by a two-step mechanism involving a catalytic nucleophile base (usually an Asp) and a catalytic proton donor (usually a Glu) that are responsible for the formation of the beta-linked glycosyl-enzyme intermediate.
This entry represents the all-beta C-terminal domain that is found in members of the glycosyl hydrolase 13 family, such as alpha-amylases and 1,4-alpha-glucan branching enzyme. This domain forms a Greek key beta-barrel fold in these enzymes [ PUBMED:7877175 ].
Branching enzyme catalyses the formation of alpha-1,6 branch points in either glycogen or starch. It has an important role in the determination of the structure of starch in plants and of glycogen in animals and bacteria [ PUBMED:12196524 ].
Gene Ontology
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
Molecular function | cation binding (GO:0043169) |
catalytic activity (GO:0003824) | |
Biological process | carbohydrate metabolic process (GO:0005975) |
Domain organisation
Below is a listing of the unique domain organisations or architectures in which this domain is found. More...
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Pfam Clan
This family is a member of clan GHD (CL0369), which has the following description:
This domain is C-terminal to the catalytic beta/alpha barrel domain. The superfamily includes the C-terminal domain of a number of sugar-lytic families.
The clan contains the following 40 members:
A_amylase_dom_C Alpha-amy_C_pro Alpha-amyl_C Alpha-amyl_C2 Alpha-amylase_C Alpha-L-AF_C AMPK1_CBM AMT4_dom_C Bac_A_amyl_C BetaGal_dom2 CBM_20 CBM_48 Collagen_bind_2 Cyc-maltodext_C DUF1923 DUF1953 DUF1964 DUF3459 DUF5597 Fucosidase_C GH97_C GHD GlgX_C Glyc_hyd_38C_2 Glyco_hyd_101C Glyco_hydro38C2 Glyco_hydro_30C Glyco_hydro_36C Glyco_hydro_42C Glyco_hydro_5_C HepII_C hGDE_central Lact_bio_phlase LBP_C Malt_amylase_C Melibiase_2_C Melibiase_C MGTA_C Pullul_strch_C SpuA_CAlignments
We store a range of different sequence alignments for families. As well as the seed alignment from which the family is built, we provide the full alignment, generated by searching the sequence database (reference proteomes) using the family HMM. We also generate alignments using four representative proteomes (RP) sets and the UniProtKB sequence database. More...
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We make a range of alignments for each Pfam-A family. You can see a description of each above. You can view these alignments in various ways but please note that some types of alignment are never generated while others may not be available for all families, most commonly because the alignments are too large to handle.
Seed (242) |
Full (11168) |
Representative proteomes | UniProt (42498) |
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RP15 (1598) |
RP35 (5198) |
RP55 (10748) |
RP75 (17667) |
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PP/heatmap | 1 |
1Cannot generate PP/Heatmap alignments for seeds; no PP data available
Key:
available,
not generated,
— not available.
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We make all of our alignments available in Stockholm format. You can download them here as raw, plain text files or as gzip-compressed files.
Seed (242) |
Full (11168) |
Representative proteomes | UniProt (42498) |
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RP15 (1598) |
RP35 (5198) |
RP55 (10748) |
RP75 (17667) |
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Raw Stockholm | |||||||
Gzipped |
You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.
HMM logo
HMM logos is one way of visualising profile HMMs. Logos provide a quick overview of the properties of an HMM in a graphical form. You can see a more detailed description of HMM logos and find out how you can interpret them here. More...
Trees
This page displays the phylogenetic tree for this family's seed alignment. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed alignment.
Note: You can also download the data file for the tree.
Curation and family details
This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.
Curation
Seed source: | ref [2] |
Previous IDs: | alpha-amylase_C; |
Type: | Domain |
Sequence Ontology: | SO:0000417 |
Author: |
Sonnhammer ELL |
Number in seed: | 242 |
Number in full: | 11168 |
Average length of the domain: | 93.6 aa |
Average identity of full alignment: | 26 % |
Average coverage of the sequence by the domain: | 13.57 % |
HMM information
HMM build commands: |
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 61295632 -E 1000 --cpu 4 HMM pfamseq
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Model details: |
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Model length: | 96 | ||||||||||||
Family (HMM) version: | 21 | ||||||||||||
Download: | download the raw HMM for this family |
Species distribution
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Structures
For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the Alpha-amylase_C domain has been found. There are 227 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein sequence.
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AlphaFold Structure Predictions
The list of proteins below match this family and have AlphaFold predicted structures. Click on the protein accession to view the predicted structure.