TMB Library of Nucleosome Simulations

Area of Science:

• Structural Biology
• Computational Biology
• Genomics

Background:

• Nucleosomes are fundamental units of chromatin, packaging DNA in eukaryotic genomes.
• Understanding nucleosome structure and dynamics is crucial for gene regulation and DNA-protein interactions.
• The vast combinatorial possibilities of DNA sequences pose challenges for comprehensive nucleosome studies.

Purpose of the Study:

• To introduce the TMB Library, a novel resource of nucleosome simulations.
• To present a meta-analysis of extensive all-atom molecular dynamics simulations of nucleosomes.
• To provide a reference for future comparative nucleosome simulations and demonstrate iBIOMES Lite.

Main Methods:

• Meta-analysis of over 20 microseconds of all-atom molecular dynamics simulations.
• Inclusion of 518 distinct nucleosome simulation realizations in the TMB Library.
• Data provision via iBIOMES Lite, including dewatered trajectories, RMSD, and DNA helical parameters.

Main Results:

• Nucleosomal DNA adopts a restricted left-handed superhelix conformation.
• Individual base conformations are not more restricted than free DNA; helical parameters are within thermal motion ranges.
• Evidence of DNA kinking and sequence-dependent structural/dynamic effects in nucleosomes, detectable even in short simulations.

Conclusions:

• The TMB Library provides a basis for comparative nucleosome simulation studies.
• Findings enhance understanding of DNA binding by proteins and drugs.
• Short simulations are sufficient to detect sequence effects and DNA kinking within nucleosomes.