<p>This domain represents a conserved region of approximately 60 residues in length within nucleolar GTP-binding protein 1 (NOG1). The NOG1 family includes eukaryotic, bacterial and archaeal proteins. In <taxon tax_id="4932">Saccharomyces cerevisiae</taxon>, the NOG1 gene has been shown to be essential for cell viability, suggesting that NOG1 may play an important role in nucleolar functions. In particular, NOG1 is believed to be functionally linked to ribosome biogenesis, which occurs in the nucleolus. In eukaryotes, NOG1 mutants were found to disrupt the biogenesis of the 60S ribosomal subunit [<cite idref="PUB00014934"/>].</p><p>The DRG and OBG proteins as well as the prokaryotic NOG-like proteins are homologous throughout their length to the amino half of eukaryotic NOG1, which contains the GTP binding motifs (<db_xref db="INTERPRO" dbkey="IPR006073"/>); the N-terminal GTP-binding motif is required for function.</p>