NucleosomeDB - a database of 3D nucleosome structures and their complexes with comparative analysis toolkit

Nucleosomes are basic building blocks of chromatin, comprising DNA wrapped around an octamer of eight histone proteins. They play key roles in DNA compaction, epigenetic mark up of the genome and actively participate in chromatin dynamics. X-ray and later cryo-EM studies have contributed greatly to our understanding of nucleosome structure, their interactions and dynamics. With over 470 nucleosome containing structures in the Protein Data Bank there is a wealth of information to be gleaned from these structures, especially through comparative analysis. However, due to the variability in their representation (chain naming, residue numbering, other artifacts), these structures cannot be systematically analyzed "as is". To address this issue, we developed a framework for analyzing and classifying nucleosome structures and their complexes, resulting in the creation of the NucleosomeDB database and the corresponding web-service. NucleosomeDB allows researchers to search, explore, and compare nucleosomes with each other, despite differences in composition and peculiarities of their representation. By utilizing the information contained within the NucleosomeDB, researchers can gain valuable insights into how nucleosomes interact with DNA and other proteins, assess the implications of mutations and protein binding on nucleosome structure. The detailed information contained within NucleosomeDB can contribute to a better understanding of the structure and function of nucleosomes, and ultimately, the functioning of chromatin and gene regulation. NucleosmeDB is freely available at https://nucldb.intbio.org.