Answers are grounded in this paper and cite their sources.
Flow linear dichroism measurements extended into the vacuum uv region yield inclinations for the base normal from the helix axis of 21 degrees for dA and 40 degrees for dT in the X-form of poly(dAdT).poly(dAdT). These inclination angles are similar to the B form of the synthetic polymer, but the axes around which the bases incline are different. Hydrogen-bonded base pairs are consistent with the geometry for the standard B, C, D, and Z forms of natural DNA, but will not fit into the A form. Fourier transform ir spectra indicate that the X form has sugar pucker and phosphate geometry similar to B-form DNA, and supports the dinucleotide repeat with two kinds of phosphates seen in earlier work, in analogy to Z-form DNA. Clearly, X-form DNA has a unique geometry.
No takes yet. Share an insight, caveat, or question.
Riazance‐Lawrence et al. (1994) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: