This entry represents a type of kelch sequence motif that comprises one β-sheet blade.

Kelch is a 50-residue motif, named after the Drosophila mutant in which it was first identified [ PUBMED:8453663 ]. This sequence motif represents one β-sheet blade, and several of these repeats can associate to form a β-propeller. … expand

This entry represents a type of kelch sequence motif that comprises one β-sheet blade.

Kelch is a 50-residue motif, named after the Drosophila mutant in which it was first identified [ PUBMED:8453663 ]. This sequence motif represents one β-sheet blade, and several of these repeats can associate to form a β-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 β-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 antiparallel β-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 ].