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11  structures 55  species 0  interactions 274  sequences 39  architectures

Family: AIDA (PF16168)

Summary: Adhesin of bacterial autotransporter system, probable stalk

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Adhesin of bacterial autotransporter system, probable stalk Provide feedback

The AIDA repeat is found on bacterial autotransporter proteins. As the repeat is short and occurs multiple times, it is likely to be the region of the transporter that acts as the stalk between the beta-barrel inserted into the membrane and the N-terminal head domain.

Literature references

  1. Sherlock O, Schembri MA, Reisner A, Klemm P;, J Bacteriol. 2004;186:8058-8065.: Novel roles for the AIDA adhesin from diarrheagenic Escherichia coli: cell aggregation and biofilm formation. PUBMED:15547278 EPMC:15547278

  2. Fang Y, Ngeleka M, Middleton DM, Simko E;, Vet Microbiol. 2005;109:65-73.: Characterization and immuno-detection of AIDA-I adhesin isolated from porcine Escherichia coli. PUBMED:15950405 EPMC:15950405

  3. Benz I, Schmidt MA;, Mol Microbiol. 1992;6:1539-1546.: AIDA-I, the adhesin involved in diffuse adherence of the diarrhoeagenic Escherichia coli strain 2787 (O126:H27), is synthesized via a precursor molecule. PUBMED:1625582 EPMC:1625582

  4. Selkrig J, Mosbahi K, Webb CT, Belousoff MJ, Perry AJ, Wells TJ, Morris F, Leyton DL, Totsika M, Phan MD, Celik N, Kelly M, Oates C, Hartland EL, Robins-Browne RM, Ramarathinam SH, Purcell AW, Schembri MA, Strugnell RA, Henderson IR, Walker D, Lithgow T;, Nat Struct Mol Biol. 2012;19:506-510.: Discovery of an archetypal protein transport system in bacterial outer membranes. PUBMED:22466966 EPMC:22466966

  5. Farthing MJ;, Best Pract Res Clin Gastroenterol. 2004;18:233-239.: Bugs and the gut: an unstable marriage. PUBMED:15123066 EPMC:15123066

This tab holds annotation information from the InterPro database.

InterPro entry IPR030930

Adhesin involved in diffuse adherence (AIDA-I) belongs to the group of monomeric autotransporters (AT) and is an important virulence factor that mediates auto-aggregation, biofilm formation, adhesion and invasion into host cells [ PUBMED:15547278 , PUBMED:15950405 , PUBMED:1625582 , PUBMED:24841284 ]. The AIDA repeat is found on bacterial autotransporter proteins. As the repeat is short and occurs multiple times, it is likely to be the region of the transporter that acts as the stalk between the beta-barrel inserted into the membrane and the N-terminal head domain.

Domain organisation

Below is a listing of the unique domain organisations or architectures in which this domain is found. More...

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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.

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You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.

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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...


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.

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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 View help on the curation process

Seed source: Pfam-B_784 (release 27.0)
Previous IDs: none
Type: Repeat
Sequence Ontology: SO:0001068
Author: Coggill P
Number in seed: 11
Number in full: 274
Average length of the domain: 56.50 aa
Average identity of full alignment: 38 %
Average coverage of the sequence by the domain: 14.14 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 61295632 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 27.0 27.0
Trusted cut-off 27.5 27.0
Noise cut-off 26.7 26.9
Model length: 63
Family (HMM) version: 8
Download: download the raw HMM for this family

Species distribution

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Colour assignments

Archea Archea Eukaryota Eukaryota
Bacteria Bacteria Other sequences Other sequences
Viruses Viruses Unclassified Unclassified
Viroids Viroids Unclassified sequence Unclassified sequence


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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 AIDA domain has been found. There are 11 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.

Protein Predicted structure External Information
P33924 View 3D Structure Click here
P39180 View 3D Structure Click here
P52143 View 3D Structure Click here
P77552 View 3D Structure Click here