Insights on the binding mechanisms and structural dynamics of protamine-DNA interaction.

Abstract

It has been more than a century since the protamines were found. Protamine continues to exist as a nucleo-protamine complex, similar to how the histone does. In sperm cells of vertebrates, protamine binds to DNA to produce compact chromatin. A more densely packed chromatin is produced when protamines replace histones. It is known that protamine is found in the DNA; however, its precise position inside DNA is not clearly known. Protamine may be bound to DNA in the major groove, according to some studies, while others contend that it is located in the minor groove. Also unknown is the precise physics underlying how protamines force histones out of sperm cells. In this work, an integrated view of the nucleo-protein complex formation regarding protamine's binding location in DNA and the phenomena associated with protamine's binding to DNA which is initiated with the eviction of the histones from the coiled chromatin is presented.