Asx Motif

Motif Glossary

Asx Motif


A motif of five consecutive residues and two H-bonds in which there is:

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sc1-3, 1-4   sc1-3, 1-5   sc1-4, 1-4   sc1-4, 1-5


These encompass the four different possible patterns of hydrogen bonding for each of Asp and Asn:

(sc = side-chain)


Wan and Milner-White, J. Mol. Biol. 286:1633-1649 (1999)


1. The total number of Asx Motifs is less than the sum of the instances of the sub-categories as individual instances of the motif with an additional mainchain–mainchain H-bond can fall into more than one sub-category.

2. The Asx Motif is analogous to the ST Motif, with the oxygen of the acid or amide side-chain replacing that of the hydroxyl.


The motif is most often found at the N-termini of α-helices.