InterPro domain: IPR004881

This entry contains Escherichia coli (strain K12) RsgA, which plays a role in the late maturation steps of the functional core of the 30S ribosomal subunit. It removes RbfA from mature, but not immature, 30S ribosomes in a GTP-dependent manner [ 1 , 2 ], and binds the 30S subunit making contact with the head, platform and rRNA helix 44 [ 3 , 4 ]. RsgA (sometimes known as YjeQ or EngC) is an unusual circulary permuted GTPase that catalyzes rapid hydrolysis of GTP with a slow catalytic turnover. It is dispensible for viability, but important for overall fitness. The intrinsic GTPase activity is stimulated by the presence of 30S (160-fold increase in k _cat ) or 70S (96 fold increase in k _cat ) ribosomes [ 5 ]. The GTPase is inhibited by aminoglycoside antibiotics such as neomycin and paromycin [ 6 ] streptomycin and spectinomycin [ 7 ]. This inhibition is not due to competition for binding sites on the 30S or 70S ribosome [ 8 ].

A mitochondrial version of RsgA has been characterized from Arabidopsis [ 8 ].

1. RsgA releases RbfA from 30S ribosome during a late stage of ribosome biosynthesis. EMBO J. 30, 104-14
2. The C-terminal helix in the YjeQ zinc-finger domain catalyzes the release of RbfA during 30S ribosome subunit assembly. RNA 21, 1203-16
3. Structural basis for the function of a small GTPase RsgA on the 30S ribosomal subunit maturation revealed by cryoelectron microscopy. Proc. Natl. Acad. Sci. U.S.A. 108, 13100-5
4. Cryo-electron microscopy structure of the 30S subunit in complex with the YjeQ biogenesis factor. RNA 17, 2026-38
5. Studies of the interaction of Escherichia coli YjeQ with the ribosome in vitro. J. Bacteriol. 186, 1381-7
6. A novel GTPase activated by the small subunit of ribosome. Nucleic Acids Res. 32, 5303-9
7. Characterization of the Bacillus subtilis GTPase YloQ and its role in ribosome function. Biochem. J. 389, 843-52
8. Identification of genes required for embryo development in Arabidopsis. Plant Physiol. 135, 1206-20