| Type: | Repeat | Name: | Kelch repeat type 2 |
| Description: | Kelch is a 50-residue motif, named after the Drosophila mutant in which it was first identified []. 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, creating a 6-bladed beta-propeller. 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 [, ], and in galactose oxidase from the fungus Dactylium dendroides[, ]. 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 [].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; 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 []. 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 [].This entry represents a type of kelch sequence motif that comprises one beta-sheet blade. | Short Name: | Kelch_2 |
