Table 3. Pucker distributions for TTA/UUAs of all type-1 loops.

	1KF1-a	1KF1-b	1KF1-c	1K8P	3IBK	3CDM-a	3CDM-b	3CDM-c	3CDM-d	3CE5	3SC8	3UYH	3T5E-a
T	C1’-exo	C1’-exo	C1’-exo	C1’-exo	C1’-exo	C1’-exo	C4’-exo	C1’-exo	C1’-exo	C1’-exo	C1’-exo	C1’-exo	C2’-endo
T	C3’-endo	C3’-endo	C3’-endo	C3’-endo	C3’-endo	C3’-endo	C3’-endo	C3’-endo	C3’-endo	C3’-endo	C3’-endo	C3’-endo	C3’-endo
A	C2’-endo	C2’-endo	C2’-endo	C2’-endo	C2’-endo	C2’-endo	C2’-endo	C2’-endo	C1’-exo	C2’-endo	C2’-endo	C2’-endo	C2’-endo
	3T5E-b	3T5E-c	4DA3	4DAQ	3R6R-a	3R6R-b	3R6R-c	4FXM-a	4FXM-b	4FXM-c	4G0F-a	4G0F-b	4G0F-c
T	C1’-exo	C2’-endo	C1’-exo	C1’-exo	C1’-exo	C1’-exo	C4’-exo	C2’-endo	C1’-exo	C1’-exo	C2’-endo	C2’-endo	C2’-endo
T	C3’-endo	C3’-endo	C3’-endo	C3’-endo	C3’-endo	C3’-endo	C3’-endo	C3’-endo	C3’-endo	C3’-endo	C3’-endo	C3’-endo	C3’-endo
A	C2’-endo	C2’-endo	C2’-endo	C2’-endo	C2’-endo	C2’-endo	C2’-endo	C2’-endo	C2’-endo	C2’-endo	C1’-exo	C1’-exo	C2’-endo

Yellow indicates a sugar which deviates from the consensus pucker conformation. Lower-case letters denote crystallographically unique type-1 loops within a single crystal structure.