Table 3

Statistics on the occurrence of different combinations of β-turns within the common π-turns.

π-turn

Multiple β-turns with their designationsa


π-HB

AAAa (350)

I-I-X (270), X-I-X (60), I-X-X (17)

PgAA (52)

II-X-X (40), II-X-I (8), X-X-I (1)

AAAA (33)

I-X-X (21), I-I-X (6), I-I-I (2), X-I-I (1), X-I-X (1)

π-NHB

AEAA (316)

X-X-I (253), VIII-X-I (45), VIII-X-X (4), X-VIa2-I (1)

EAAa (281)

X-I-X (270)

EAAA (219)

X-I-I (156), X-I-X (44), X-X-I (12)

EAAE (176)

X-I-X (130), X-I-VIII (16), VIa1-X-VIII (1), VIa1-I-X (1)

AAaA (171)

I-X-X (146)

AEEa (167)

X-X-II (131), VIII-X-II (20), X-VIb-II (1)


The number of occurrence is given in parentheses.

a X indicates no characteristic β-turn. The conventional nomenclature of β-turns (viz., turn types I, II, VI, VIII, etc.) has been used. A multiple turn I-I-X indicates that there is a type I turn involving residues (i)-(i+3), another type I involving (i+1)-(i+4), and the turn type involving (i+2)-(i+5) does not conform to any β-turn type.

Dasgupta and Chakrabarti BMC Structural Biology 2008 8:39   doi:10.1186/1472-6807-8-39

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