title: Structural insights into cell cycle control by essential GTPase Era.
abstract: Era (Escherichia coli Ras-like protein), essential for bacterial cell viability, is composed of an N-terminal GTPase domain and a C-terminal KH domain. In bacteria, it is required for the processing of 16S ribosomal RNA (rRNA) and maturation of 30S (small) ribosomal subunit. Era recognizes 10 nucleotides (1530GAUCACCUCC1539) near the 3' end of 16S rRNA and interacts with helix 45 (h45, nucleotides 1506-1529). GTP binding enables Era to bind RNA, RNA binding stimulates Era's GTP-hydrolyzing activity, and GTP hydrolysis releases Era from matured 30S ribosomal subunit. As such, Era controls cell growth rate via regulating the maturation of the 30S ribosomal subunit. Ribosomes manufacture proteins in all living organisms. The GAUCA sequence and h45 are highly conserved in all three kingdoms of life. Homologues of Era are present in eukaryotic cells. Hence, the mechanism of bacterial Era action also sheds light on the cell cycle control of eukaryotes.
authors.affiliation: Biomolecular Structure Section, Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD, USA.
authors.forename: Xinhua
authors.initials: X
authors.lastname: Ji
mesh_terms: D059447:Cell Cycle Checkpoints; D004926:Escherichia coli / Q000201:enzymology* / Q000502:physiology; D029968:Escherichia coli Proteins / Q000378:metabolism* / Q000502:physiology; D019204:GTP-Binding Proteins / Q000378:metabolism* / Q000502:physiology; D011487:Protein Conformation; D012336:RNA, Ribosomal, 16S / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism* / Q000502:physiology; D054680:Ribosome Subunits, Small, Bacterial / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; D012336:RNA, Ribosomal, 16S; D016601:RNA-Binding Proteins; C068027:era protein, E coli; D019204:GTP-Binding Proteins
keywords: 16S rRNA; 30S ribosomal subunit; cell cycle control; ribosome biogenesis