How do I build an A- or B-form DNA model with a particular base sequence?

[xiangjun]

The easiest way to build a canonical double helical structure of specific sequence is to use the fiber program. The default option is structure #4, which corresponds to the calf thymus B-DNA double helix due to Struther Arnott. To build the A-form, the user should choose structure #1. Coordinates of these two structures are taken from Struther Arnott: "Polynucleotide secondary structures: an historical perspective", pp. 1-38 in "Oxford Handbook of Nucleic Acid Structure", edited by Stephen Neidle (Oxford Press, 1999).

For example, to build an A-DNA structure of sequence 'AAGCTTTC', one can do the following:

Code: [Select]

fiber -a -seq=AAGCTTTC fa.pdb
Note the -seq option is added as of v2.1.