Table 1.

Secondary structure classifications

Class	Definition	Fragments
H1	Start of a helix	CHH or EHH
H2	Within a helix	HHH
H3	End of a helix	HHC or HHE
E1	Start of a strand	CEE or HEE
E2	Within a strand	EEE
E3	End of a strand	EEC or EEH
C1	Start of a coil	HCC or ECC
C2	Within a coil	CCC
C3	End of a coil	CCH or CCE

The class code is given in column 1 with a longer description in column 2. The secondary structures that qualify for this class are given in column 3, where H is helix, C is coil and E is strand. The central residue/codon of the fragment is assigned to that class.