polypeptide_secondary_structure serine_threonine_staple_motif sequence A motif of four or five consecutive residues and one H-bond in which: residue(i) is Serine (S) or Threonine (T), the side-chain OH of residue(i) is H-bonded to the main-chain CO of residue(i3) or (i4), Phi angles of residues(i1), (i2) and (i3) are negative. serine threonine staple motif BS:00230 st_staple SO:0001127