YB-1 is capable of forming extended nanofibrils.

Here we are the first to report that multifunctional Y-box binding protein 1 (YB-1) forms extended fibrils with a diameter of 15-20 nm. The YB-1 fibrils were visualized by atomic force and electron microscopy after 1-h incubation in solution with 2 M LiCl. Their length grew with incubation time and could exceed 10 microm; their shape is helical or zigzag-like. They possess polarity and tend to associate with one another to give structures of a higher order, like ribbons or bundles. The YB-1 fibrillar architecture has a distinct periodicity with a repeat unit of about 52 nm.