InterPro domain: IPR030388

Era (E. coli Ras-like protein) is a small G-protein widely conserved in eubacteria and eukaryotes. It is essential for bacterial cell viability and is required for the maturation of 16S rRNA and assembly of the 30S ribosomal subunit [ 1 ]. Era couples cell growth with cytokinesis and plays a role in cell division and energy metabolism. Era contains an N-terminal GTPase domain and a C-terminal distinct derivative of the type-II RNA-binding KH domain [ 2 , 3 , 4 , 5 ]. Both domains are important for Era function. Era is functionally able to compensate for deletion of RbfA, a cold-shock adaptation protein that is required for efficient processing of the 16S rRNA.

The Era-type GTPase domain consists of a central six-stranded beta-sheetflanked by five alpha-helices, in which the GTP-binding site is located. Guanine nucleotide molecules interact with highly conserved G protein regions G1-G5 [ 6 ].

1. Interaction of Era with the 30S ribosomal subunit implications for 30S subunit assembly. Mol. Cell 18, 319-29
2. Classification and evolution of P-loop GTPases and related ATPases. J. Mol. Biol. 317, 41-72
3. Analysis of guanine nucleotide binding and exchange kinetics of the Escherichia coli GTPase Era. J. Bacteriol. 182, 3460-6
4. Structure of ERA in complex with the 3' end of 16S rRNA: implications for ribosome biogenesis. Proc. Natl. Acad. Sci. U.S.A. 106, 14843-8
5. The Era GTPase recognizes the GAUCACCUCC sequence and binds helix 45 near the 3' end of 16S rRNA. Proc. Natl. Acad. Sci. U.S.A. 108, 10156-61