Summary: Outer membrane usher protein
This is the Wikipedia entry entitled "Fimbrial usher protein". More...
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Fimbrial usher protein Edit Wikipedia article
|Fimbrial Usher protein|
Structure of the type 1 pilus assembly platform FimD(25-139).
The fimbrial usher protein is involved in biogenesis of the pilus in Gram-negative bacteria. The biogenesis of fimbriae (or pili) requires a two-component assembly and transport system which is composed of a periplasmic chaperone and an outer membrane protein which has been termed a molecular 'usher'.
The usher protein has a molecular weight ranging from 86 to 100 kDa and is composed of a membrane-spanning 24-stranded beta barrel domain, reminiscent of porins, and of four periplasmic soluble domains: an N-terminal one of about 120 residues (NTD), a 'middle' domain of about 80 residues located as a soluble insertion within the beta barrel region of the sequence (plug domain) and two IG-like domains (each about 80 residues long) at the C-terminus (CTD1 and CTD2). Although the degree of sequence similarity of these proteins is not very high they share a number of characteristics. One of these is the presence of two pairs of disulfide bond-forming cysteines, the first one located in the NTD and the second in CTD2. The best conserved region of the sequence corresponds to the plug domain.
- Nishiyama M, Horst R, Eidam O, et al. (June 2005). "Structural basis of chaperone–subunit complex recognition by the type 1 pilus assembly platform FimD". EMBO J. 24 (12): 2075–86. doi:10.1038/sj.emboj.7600693. PMC 1150887. PMID 15920478.
- Hultgren SJ, Jacob-Dubuisson F, Striker R (1994). "Chaperone-assisted self-assembly of pili independent of cellular energy". J. Biol. Chem. 269 (17): 12447–12455. PMID 7909802.
- Schifferli DM, Alrutz MA (1994). "Permissive linker insertion sites in the outer membrane protein of 987P fimbriae of Escherichia coli". J. Bacteriol. 176 (4): 1099–1110. PMC 205162. PMID 7906265.
- Saier Jr MH, Van Rosmalen M (1993). "Structural and evolutionary relationships between two families of bacterial extracytoplasmic chaperone proteins which function cooperatively in fimbrial assembly". Res. Microbiol. 144 (7): 507–527. doi:10.1016/0923-2508(93)90001-I. PMID 7906046.
- Capitani G, Eidam O, Grütter MG (2006) Evidence for a novel domain of bacterial outer membrane ushers. Proteins 65 (4):816-23. doi:10.1002/prot.21147 PMID 17066380
- Phan G, Remaut H, Wang T, Allen WJ, Pirker KF, Lebedev A et al. (2011) Crystal structure of the FimD usher bound to its cognate FimC-FimH substrate. Nature 474 (7349):49-53. doi:10.1038/nature10109 PMID 21637253
Outer membrane usher protein Provide feedback
In Gram-negative bacteria the biogenesis of fimbriae (or pili) requires a two- component assembly and transport system which is composed of a periplasmic chaperone and an outer membrane protein which has been termed a molecular 'usher' [1-3]. The usher protein is rather large (from 86 to 100 Kd) and seems to be mainly composed of membrane-spanning beta-sheets, a structure reminiscent of porins. Although the degree of sequence similarity of these proteins is not very high they share a number of characteristics. One of these is the presence of two pairs of cysteines, the first one located in the N-terminal part and the second at the C-terminal extremity that are probably involved in disulphide bonds. The best conserved region is located in the central part of these proteins [4-5].
Van Rosmalen M, Saier MH Jr;, Res Microbiol. 1993;144:507-527.: Structural and evolutionary relationships between two families of bacterial extracytoplasmic chaperone proteins which function cooperatively in fimbrial assembly. PUBMED:7906046 EPMC:7906046
Huang Y, Smith BS, Chen LX, Baxter RH, Deisenhofer J;, Proc Natl Acad Sci U S A. 2009;106:7403-7407.: Insights into pilus assembly and secretion from the structure and functional characterization of usher PapC. PUBMED:19380723 EPMC:19380723
Remaut H, Tang C, Henderson NS, Pinkner JS, Wang T, Hultgren SJ, Thanassi DG, Waksman G, Li H;, Cell. 2008;133:640-652.: Fiber formation across the bacterial outer membrane by the chaperone/usher pathway. PUBMED:18485872 EPMC:18485872
External database links
This tab holds annotation information from the InterPro database.
InterPro entry IPR000015In Gram-negative bacteria the biogenesis of fimbriae (or pili) requires a two- component assembly and transport system which is composed of a periplasmic chaperone (see PROSITEDOC) and an outer membrane protein which has been termed a molecular 'usher' [PUBMED:7909802, PUBMED:7906265, PUBMED:7906046].
The usher protein is rather large (from 86 to 100 kDa) and seems to be mainly composed of membrane-spanning beta-sheets, a structure reminiscent of porins. Although the degree of sequence similarity of these proteins is not very high, they share a number of characteristics. One of these is the presence of two pairs of cysteines, the first one located in the N-terminal part and the second at the C-terminal extremity that are probably involved in disulphide bonds. The best conserved region is located in the central part of these proteins.
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
|Cellular component||membrane (GO:0016020)|
|Molecular function||transporter activity (GO:0005215)|
|Biological process||transport (GO:0006810)|
- the number of sequences which exhibit this architecture
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This example describes an architecture with one
Gladomain, followed by two consecutive
EGFdomains, and finally a single
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This clan gathers together a large set of beta barrel membrane proteins.Although these proteins have different numbers of beta strands in the barrel they have significant sequence similarity between families.
The clan contains the following 54 members:Ail_Lom Autotransporter Bac_surface_Ag Campylo_MOMP Channel_Tsx CopB DUF1302 DUF1597 DUF2320 DUF2490 DUF2860 DUF3078 DUF3138 DUF3187 DUF3308 DUF3374 DUF3575 DUF4289 DUF481 DUF560 Gcw_chp HP_OMP HP_OMP_2 KdgM LamB Legionella_OMP MipA OMP_b-brl OMP_b-brl_2 OMP_b-brl_3 OmpA_membrane Omptin OmpW Opacity OpcA OprB OprD OprF OstA_C PagL Phenol_MetA_deg Porin_1 Porin_2 Porin_4 Porin_O_P Porin_OmpG ShlB Surface_Ag_2 Toluene_X TonB_dep_Rec TraF_2 TSA Usher YfaZ
We make a range of alignments for each Pfam-A family:
- the curated alignment from which the HMM for the family is built
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1Cannot generate PP/Heatmap alignments for seeds; no PP data available
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Curation and family details
|Seed source:||MRC-LMB Genome group and Prosite|
|Author:||Bateman A, Desvaux M, Eberhardt R|
|Number in seed:||34|
|Number in full:||6892|
|Average length of the domain:||502.70 aa|
|Average identity of full alignment:||31 %|
|Average coverage of the sequence by the domain:||67.01 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||15|
|Download:||download the raw HMM for this family|
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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 Usher domain has been found. There are 10 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 seqence.
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