Summary: Kelch motif
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Kelch motif Edit Wikipedia article
|SCOP2||1gof / SCOPe / SUPFAM|
|SCOP2||1gof / SCOPe / SUPFAM|
|Galactose oxidase, central domain|
|Galactose oxidase, central domain|
The Kelch motif is a region of protein sequence found widely in proteins from bacteria and eukaryotes. This sequence motif is composed of about 50 amino acid residues which form a structure of a four stranded beta-sheet "blade". This sequence motif is found in between five and eight tandem copies per protein which fold together to form a larger circular solenoid structure called a beta-propeller domain.
Proteins containing Kelch motifs
The Kelch motif is widely found in eukaryotic and bacterial species. Notably the human genome contains around 100 proteins containing the Kelch motif. Within individual proteins the motif occurs multiple times. For example, the motif appears 6 times in Drosophila egg-chamber regulatory protein. The motif is also found in mouse protein MIPP and in a number of poxviruses. In addition, kelch repeats have been recognised in alpha- and beta-scruin, in galactose oxidase from the fungus Dactylium dendroides and in the Escherichia coli NanM protein, that is a sialic acid mutarotase.
The structure of galactose oxidase reveals that the repeated Kelch sequence motif corresponds to a 4-stranded anti-parallel beta-sheet motif that forms the repeat unit in a super-barrel structural fold commonly known as a beta propeller.
The known functions of kelch-containing proteins are diverse:
- scruin is an actin cross-linking protein;
- galactose oxidase catalyses the oxidation of the hydroxyl group at the C6 position in D-galactose;
- neuraminidase hydrolyses sialic acid residues from glycoproteins;
- NanM is a sialic acid mutarotase, involved in efficient utilisation of sialic acid by bacteria;
- kelch may have a cytoskeletal function, as it is localised to the actin-rich ring canals that connect the 15 nurse cells to the developing oocyte in Drosophila.
- Ito N, Phillips SE, Stevens C, etÂ al. (March 1991). "Novel thioether bond revealed by a 1.7 A crystal structure of galactose oxidase". Nature. 350 (6313): 87â€“90. doi:10.1038/350087a0. PMIDÂ 2002850. S2CIDÂ 4345713.
- Adams J, Kelso R, Cooley L (January 2000). "The kelch repeat superfamily of proteins: propellers of cell function". Trends Cell Biol. 10 (1): 17â€“24. doi:10.1016/S0962-8924(99)01673-6. PMIDÂ 10603472.
- Xue F, Cooley L (1993). "kelch encodes a component of intercellular bridges in Drosophila egg chambers". Cell. 72 (5): 681â€“693. doi:10.1016/0092-8674(93)90397-9. PMIDÂ 8453663.
- Way M, Sanders M, Matsudaira P, Chafel M, Knight A, Tu YH (1995). "beta-Scruin, a homologue of the actin crosslinking protein scruin, is localized to the acrosomal vesicle of Limulus sperm". J. Cell Sci. 108: 3155â€“3162. PMIDÂ 7593276.
- Way M, Sakai J, Sanders M, Garcia C, Matsudaira P (1995). "Sequence and domain organization of scruin, an actin-cross-linking protein in the acrosomal process of Limulus sperm". J. Cell Biol. 128 (1): 51â€“60. doi:10.1083/jcb.128.1.51. PMCÂ 2120335. PMIDÂ 7822422.
- Doolittle RF, Bork P (1994). "Drosophila kelch motif is derived from a common enzyme fold". J. Mol. Biol. 236 (5): 1277â€“1282. doi:10.1016/0022-2836(94)90056-6. PMIDÂ 8126718.
- Keen JN, Ito N, Phillips SE, Stevens C, Ogel ZB, McPherson MJ, Yadav KD, Knowles PF (1991). "Novel thioether bond revealed by a 1.7 A crystal structure of galactose oxidase". Nature. 350 (6313): 87â€“90. doi:10.1038/350087a0. PMIDÂ 2002850. S2CIDÂ 4345713.
- Severi E, MÃ¼ller A, Potts JR, Leech A, Williamson D, Wilson KS, Thomas GH (2008). "Sialic acid mutarotation is catalyzed by the Escherichia coli beta-propeller protein YjhT". J. Biol. Chem. 283 (8): 4841â€“4849. doi:10.1074/jbc.m707822200. PMIDÂ 18063573.
- Ito N, Phillips SE, Yadav KD, Knowles PF (1994). "Crystal structure of a free radical enzyme, galactose oxidase". J. Mol. Biol. 238 (5): 794â€“814. doi:10.1006/jmbi.1994.1335. PMIDÂ 8182749.
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Kelch motif Provide feedback
The kelch motif was initially discovered in Kelch (Q04652). In this protein there are six copies of the motif. It has been shown that Q04652 is related to Galactose Oxidase  for which a structure has been solved . The kelch motif forms a beta sheet. Several of these sheets associate to form a beta propeller structure as found in PF00064 PF00400 and PF00415.
Ito N, Phillips SE, Stevens C, Ogel ZB, McPherson MJ, Keen JN, Yadav KD, Knowles PF; , Nature 1991;350:87-90.: Novel thioether bond revealed by a 1.7 A crystal structure of galactose oxidase. PUBMED:2002850 EPMC:2002850
Internal database links
|SCOOP:||DUF1668 DUF6242 Glyoxal_oxid_N Kelch_1 Kelch_3 Kelch_4 Kelch_5 Kelch_6|
|Similarity to PfamA using HHSearch:||Kelch_1 Kelch_3 Kelch_4 Kelch_5 Kelch_6|
External database links
This tab holds annotation information from the InterPro database.
InterPro entry IPR011498
Kelch is a 50-residue motif, named after the Drosophila mutant in which it was first identified [ PUBMED:8453663 ]. This sequence motif represents one beta-sheet blade, and several of these repeats can associate to form a beta-propeller. For instance, the motif appears 6 times in Drosophila egg-chamber regulatory protein (also known as ring canal kelch protein), creating a 6-bladed beta-propeller. The motif is also found in mouse protein MIPP [ PUBMED:8453663 ] and in a number of poxviruses. In addition, kelch repeats have been recognised in alpha- and beta-scruin [ PUBMED:7593276 , PUBMED:7822422 ], and in galactose oxidase from the fungus Dactylium dendroides [ PUBMED:8126718 , PUBMED:2002850 ]. The structure of galactose oxidase reveals that the repeated sequence corresponds to a 4-stranded anti-parallel beta-sheet motif that forms the repeat unit in a super-barrel structural fold [ PUBMED:8182749 ].
The known functions of kelch-containing proteins are diverse: scruin is an actin cross-linking protein; galactose oxidase catalyses the oxidation of the hydroxyl group at the C6 position in D-galactose; and kelch may have a cytoskeletal function, as it is localised to the actin-rich ring canals that connect the 15 nurse cells to the developing oocyte in Drosophila [ PUBMED:7593276 ]. Nevertheless, based on the location of the kelch pattern in the catalytic unit in galactose oxidase, functionally important residues have been predicted in glyoxal oxidase [ PUBMED:8126718 ].
This entry represents a type of kelch sequence motif that comprises one beta-sheet blade.
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
|Molecular function||protein binding (GO:0005515)|
Below is a listing of the unique domain organisations or architectures in which this domain is found. More...
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This large clan contains proteins that contain beta propellers. These are composed of between 6 and 8 repeats. The individual repeats are composed of a four stranded sheet. The clan includes families such as WD40 Pfam:PF00400 where the individual repeats are modeled. The clan also includes families where the entire propeller is modeled such as Pfam:PF02239 usually because the individual repeats are not discernible. These proteins carry out a very wide diversity of functions including catalysis.
The clan contains the following 112 members:ANAPC1 ANAPC4_WD40 Arylesterase Arylsulfotran_2 Arylsulfotrans B_lectin BBS2_Mid BBS2_N Beta_propel Coatomer_WDAD CPSF_A CyRPA Cytochrom_D1 DCAF17 Dpp_8_9_N DPPIV_N DPPIV_rep DUF1513 DUF1668 DUF2415 DUF346 DUF3466 DUF3616 DUF3748 DUF4221 DUF4374 DUF4394 DUF4623 DUF4784 DUF4915 DUF4933 DUF4934 DUF5046 DUF5050 DUF5122 DUF5128 DUF5711 DUF839 eIF2A FG-GAP FG-GAP_2 FG-GAP_3 Frtz Ge1_WD40 Glu_cyclase_2 Glyoxal_oxid_N Gmad1 GSDH Helveticin_J HPS3_N HPS6 Hyd_WA IKI3 Itfg2 Kelch_1 Kelch_2 Kelch_3 Kelch_4 Kelch_5 Kelch_6 Lactonase Ldl_recept_b LGFP Lgl_C LVIVD Me-amine-dh_H MgpC MRJP Nbas_N NBCH_WD40 Neisseria_PilC NHL nos_propeller nos_propeller_2 Nucleoporin_N Nup160 Nup88 P1_N PALB2_WD40 PD40 Pectate_lyase22 Peptidase_S9_N PHTB1_N Phytase-like PQQ PQQ_2 PQQ_3 RAB3GAP2_N RAG2 RCC1 RCC1_2 Reg_prop RPE65 SBBP SBP56 SdiA-regulated Sema SGL SSL_N Str_synth TcdB_toxin_midN Tectonin TolB_like VID27 Vps16_N WD40 WD40_2 WD40_3 WD40_4 WD40_like WDCP YmzC
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1Cannot generate PP/Heatmap alignments for seeds; no PP data available
Key: available, not generated, — not available.
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|Seed source:||Context Domains|
|Number in seed:||41|
|Number in full:||3885|
|Average length of the domain:||49.60 aa|
|Average identity of full alignment:||24 %|
|Average coverage of the sequence by the domain:||9.22 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 61295632 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||18|
|Download:||download the raw HMM for this family|
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The tree shows the occurrence of this domain across different species. More...
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For all of the domain matches in a full alignment, we count the number that are found on all sequences in the alignment. This total is shown in the purple box.
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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 Kelch_2 domain has been found. There are 9 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.