Purification, characterization and crystallization of ERA, an essential GTPase from Escherichia coli1By acceptance of this article, the publisher or recipient acknowledges the right of the US government and its agents and contractors to retain a non-exclusive royalty-free license in and to any copyright covering the article.1

AbstractERA is an essential GTPase widely conserved in bacteria. Homologues of ERA are also present in higher eukaryotic cells. ERA is involved in bacterial cell cycle control at a point preceding cell division. In order to aid the functional investigation of ERA and to facilitate structure-function studies, we have undertaken the X-ray crystallographic analysis of this protein. Here, we report the purification and crystallization procedures and results. The purified ERA exhibits nucleotide-binding activity and GTP-hydrolytic activity. ERA is one of the very few multi-domain GTPases crystallized to date