Crystal structure of zinc-finger domain of Nanos and its functional implications.

Nanos is an RNA-binding protein that is involved in the development and maintenance of germ cells. In combination with Pumilio, Nanos binds to the 3' untranslated region of a messenger RNA and represses its translation. Nanos has two conserved Cys-Cys-His-Cys zinc-finger motifs that are indispensable for its function. In this study, we have determined the crystal structure of the zinc-finger domain of zebrafish Nanos, for the first time revealing that Nanos adopts a novel zinc-finger structure. In addition, Nanos has a conserved basic surface that is directly involved in RNA binding. Our results provide the structural basis for further studies to clarify Nanos function.