Helical structure of xylose-DNA

Area of Science:

• Synthetic biology
• Systems chemistry
• Biochemistry

Background:

• Growing interest in modified nucleotides for enzymatically stable artificial nucleic acids.
• Xylose-DNA, a potential candidate, replaces 2'-deoxy-beta-D-ribo-furanose with 2'-deoxy-beta-D-xylo-furanose.
• Investigating the structural and dynamic properties of artificial nucleic acids is crucial for their applications.

Purpose of the Study:

• To present the helical structure and conformational analysis of xylose-DNA.
• To understand the dynamic behavior and stability of xylose-DNA.
• To compare the properties of xylose-DNA with natural ribose-based DNA.

Main Methods:

• 35 ns molecular dynamics (MD) simulations of a 29-base-pair DNA duplex.
• Analysis of helical structure, conformational transitions, and backbone dynamics.
• Examination of base pairing and stacking interactions.

Main Results:

• Observed a remarkable conformational transition from a right-handed to a left-handed helix in xylose-DNA.
• The left-handed xylose-DNA helix is highly dynamic, exhibiting screwing and unscrewing motions.
• Sugar pucker changes induced helical alterations, affecting backbone angles while maintaining Watson-Crick base pairing and stacking.

Conclusions:

• Xylose-DNA demonstrates chiral orthogonality with ribose-based DNA (episomes).
• Natural ribose-based DNA remains unsurpassed in terms of stability and compactness for information storage.
• Modified nucleotides offer unique structural and dynamic properties for artificial nucleic acid development.