  Positioning of nucleosomes along eukaryotic genomes plays an important role
in their organization and regulation. There are many different factors
affecting the location of nucleosomes. Some can be viewed as preferential
binding of a single nucleosome to different locations along the DNA and some as
interactions between neighboring nucleosomes. In this study we analyzed how
well nucleosomes are positioned along the DNA as a function of strength of the
preferential binding, correlation length of the binding energy landscape,
interactions between neighboring nucleosomes and others relevant system
properties. We analyze different scenarios: designed energy landscapes and
generically disordered ones and derive conditions for good positioning. Using
analytic and numerical approaches we find that, even if the binding preferences
are very weak, synergistic interplay between the interactions and the binding
preferences is essential for a good positioning of nucleosomes, especially on
correlated energy landscapes. Analyzing empirical energy landscape, we discuss
relevance of our theoretical results to positioning of nucleosomes on DNA
\emph{in vivo.}
