[2] 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.

The motif is also found in mouse protein MIPP[3] and in a number of poxviruses.

In addition, kelch repeats have been recognised in alpha- and beta-scruin,[4][5] in galactose oxidase from the fungus Dactylium dendroides,[6][7] and in the Escherichia coli NanM protein, a sialic acid mutarotase.

[8] 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.