

DNA in ASCII - sal9000
http://ocw.mit.edu/courses/mathematics/18-417-introduction-to-computational-molecular-biology-fall-2004/chp_compbio2.jpg

======
maxharris
They might as well call it a picture of a rope, or the twisted pair of an
ethernet cable, or something equally fanciful.

The picture is horribly wrong because:

\- It's left-handed and 10bp/turn. Only Z-DNA is left-handed, so it's obvious
(to anyone that's taken a course in biochemistry) that they're missing two
base-pair "rungs".

\- If it's not supposed to be Z-DNA, where are the major/minor grooves?

In fact, none of the known unstrained DNA geometries match the picture: A-form
DNA has 11bp/turn, B-form DNA has 10.5bp/turn, and Z-form DNA is 12bp/turn.

"Artists" get this wrong frequently, but without any good reason because these
structures have been well-known for several decades. Furthermore, incorrect
pictures undermine biochemistry's beautiful basis: _structure determines
function_. Would it have troubled them that much to search for correct
information on the Internet (or a book)?

See
[https://secure.wikimedia.org/wikipedia/en/wiki/File:A-DNA,_B...](https://secure.wikimedia.org/wikipedia/en/wiki/File:A-DNA,_B-
DNA_and_Z-DNA.png) and <http://en.wikipedia.org/wiki/Z-DNA>

