Each residue must be separated by - (minus).
x represents any amino acid.
[DE] means either D or E.
{FWY} means any amino acid except for F, W and Y.
A(2,3) means that A appears 2 to 3 times consecutively.
The pattern string must be terminated with . (period).
e.g., C-x-{C}-[DN]-x(2)-C-x(5)-C-C.