title: Prediction of nucleosome rotational positioning in yeast and human genomes based on sequence-dependent DNA anisotropy.
abstract: BACKGROUND
  An organism's DNA sequence is one of the key factors guiding the positioning of nucleosomes within a cell's nucleus. Sequence-dependent bending anisotropy dictates how DNA is wrapped around a histone octamer. One of the best established sequence patterns consistent with this anisotropy is the periodic occurrence of AT-containing dinucleotides (WW) and GC-containing dinucleotides (SS) in the nucleosomal locations where DNA is bent in the minor and major grooves, respectively. Although this simple pattern has been observed in nucleosomes across eukaryotic genomes, its use for prediction of nucleosome positioning was not systematically tested.
  
  
  RESULTS
  We present a simple computational model, termed the W/S scheme, implementing this pattern, without using any training data. This model accurately predicts the rotational positioning of nucleosomes both in vitro and in vivo, in yeast and human genomes. About 65 - 75% of the experimentally observed nucleosome positions are predicted with the precision of one to two base pairs. The program is freely available at http://people.rit.edu/fxcsbi/WS_scheme/. We also introduce a simple and efficient way to compare the performance of different models predicting the rotational positioning of nucleosomes.
  
  
  CONCLUSIONS
  This paper presents the W/S scheme to achieve accurate prediction of rotational positioning of nucleosomes, solely based on the sequence-dependent anisotropic bending of nucleosomal DNA. This method successfully captures DNA features critical for the rotational positioning of nucleosomes, and can be further improved by incorporating additional terms related to the translational positioning of nucleosomes in a species-specific manner.
authors.affiliation: Thomas H, Gosnell School of Life Sciences, Rochester Institute of Technology, Rochester, NY 14623, USA. fxcsbi@rit.edu.
authors.forename: Feng
authors.initials: F
authors.lastname: Cui
authors.forename: Linlin
authors.initials: L
authors.lastname: Chen
authors.forename: Peter R
authors.initials: PR
authors.lastname: LoVerso
authors.forename: Victor B
authors.initials: VB
authors.lastname: Zhurkin
mesh_terms: D016880:Anisotropy; D001483:Base Sequence; D042002:Chromatin Assembly and Disassembly; D004271:DNA, Fungal / Q000235:genetics*; D015894:Genome, Human / Q000235:genetics*; D006801:Humans; D008957:Models, Genetic; D009707:Nucleosomes / Q000235:genetics*; D012399:Rotation; D012441:Saccharomyces cerevisiae / Q000235:genetics*
chemical_list: D004271:DNA, Fungal; D009707:Nucleosomes