An HflX-Type GTPase from Sulfolobus solfataricus Binds to the 50S Ribosomal Subunit in All Nucleotide-Bound States

HflX GTPases are found in all three domains of life, the Bacteria , Archaea , and Eukarya . HflX from Escherichia coli has been shown to bind to the 50S ribosomal subunit in a nucleotide-dependent manner, and this interaction strongly stimulates its GTPase activity. We recently determined the structure of an HflX ortholog from the archaeon Sulfolobus solfataricus (SsoHflX). It revealed the presence of a novel HflX domain that might function in...