An essential GTPase that binds both GDP and GTP, with rapid nucleotide exchange. Plays a role in 16S rRNA processing and 30S ribosomal subunit biogenesis and possibly also in cell cycle regulation and energy metabolism (By similarity). The GTPase is stimulated about 6-fold in the presence of a 12 nucleotide 16S rRNA C-terminal fragment. Mutations in the rRNA sequence obviate stimulation. RNA-binding depends on GTP-binding by the GTPase domain. May function as a checkpoint for assembly of the 30S ribosomal subunit. Monomer. Belongs to the TRAFAC class TrmE-Era-EngA-EngB-Septin-like GTPase superfamily. Era GTPase family.