The glycine-rich domain of nucleolin has an unusual supersecondary structure responsible for its RNA-helix-destabilizing properties.

Nucleolin, a major nucleolar protein implicated in preribosome assembly and transcriptional regulation, possesses a C-terminal domain unusually rich in glycine, arginine, and phenylalanine residues. A polypeptide (p10), corresponding to this domain, has been synthesized by means of an Escherichia coli expression system and purified to homogeneity. Nitrocellulose binding assays have clearly shown that this domain of nucleolin is capable of interacting with RNA, and indeed all nucleic acids tested, in an efficient but nonspecific manner.