InterPro domain: IPR015947

This superfamily represents domains with a PUA-like structure, consisting of a pseudo-barrel composed of mixed folded sheets of five strands. This structural motif is found in:

• PUA-containing proteins.
• The N-terminal of ATP sulphurylases, which contains extra structures, some similar to the PK beta-barrel domain [ 1 ].
• Several bacterial hypothetical proteins, such as the N-terminal domain of YggJ [ 2 ].

The PUA (PseudoUridine synthase and Archaeosine transglycosylase) domain was named after the proteins in which it was first found [ 3 ]. PUA is a highly conserved RNA-binding motif found in a wide range of archaeal, bacterial and eukaryotic proteins, including enzymes that catalyse tRNA and rRNA post-transcriptional modifications, proteins involved in ribosome biogenesis and translation, as well as in enzymes involved in proline biosynthesis [ 4 , 5 ]. The structures of several PUA-RNA complexes reveal a common RNA recognition surface, but also some versatility in the way in which the motif binds to RNA [ 6 ]. PUA motifs are involved in dyskeratosis congenita and cancer, pointing to links between RNA metabolism and human diseases [ 7 ].

1. Crystal structure of ATP sulfurylase from Saccharomyces cerevisiae, a key enzyme in sulfate activation. EMBO J. 20, 316-29
2. Functional assignment based on structural analysis: crystal structure of the yggJ protein (HI0303) of Haemophilus influenzae reveals an RNA methyltransferase with a deep trefoil knot. Proteins 53, 329-32
3. Novel predicted RNA-binding domains associated with the translation machinery. J. Mol. Evol. 48, 291-302
4. The structure of the RNA m5C methyltransferase YebU from Escherichia coli reveals a C-terminal RNA-recruiting PUA domain. J. Mol. Biol. 360, 774-87
5. The RNA-binding PUA domain of archaeal tRNA-guanine transglycosylase is not required for archaeosine formation. J. Biol. Chem. 281, 6993-7001
6. The PUA domain - a structural and functional overview. FEBS J. 274, 4972-84
7. Crystal structure of an H/ACA box ribonucleoprotein particle. Nature 443, 302-7