Parallel stranded DNA under the scanning tunnelling microscope.
Using scanning tunnelling microscopy, we have directly observed parallel stranded DNA helixes of 43 nucleotides in length. The double helix is right-handed and has an average spacing, 17.43 A (+/- 1 S.D.: 2.30 A), and an average apparent depth, 4.79 A (+/- 1 S.D.: 1.04 A) for each groove. The average pitch of the helical turn is 34 A (+/- 1 S.D.: 3.35 A) and consists of no more than ten base pairs. The diameter of the helix is approx. 17-20 A. Our results provide direct evidence for the existence of a parallel structure of DNA in vitro and some details of its fine structure.
Zhu
J D
JD
Shanghai Institute of Cell Biology, Shanghai Open Laboratory of Life Sciences, China.
Li
M Q
MQ
Xiu
L Z
LZ
Zhu
J Q
JQ
Hu
J
J
Gu
M M
MM
Xu
Y L
YL
Zhang
L P
LP
Huang
Z Q
ZQ
Chernov
B K
BK
D001483:Base Sequence; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004247:DNA / Q000737:chemistry / Q000648:ultrastructure*; D016252:Microscopy, Scanning Tunneling; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation
D004247:DNA