<p>Domain 2 of the ribosomal protein S5 has a left-handed, 2-layer alpha/beta fold with a core structure consisting of beta(3)-alpha-beta-alpha. Domains with this fold are found in numerous RNA/DNA-binding proteins, as well as in kinases from the GHMP kinase family. Proteins containing this alpha/beta fold domain include: </p><ul><li>Translational machinery components (ribosomal proteins S5 and S9, and domain IV of elongation factors EF-G and eEF-2) [<cite idref="PUB00034480"/>].</li><li>Ribonuclease P protein (RNase P) [<cite idref="PUB00034481"/>].</li><li>Ribonuclease PH (domain 1) [<cite idref="PUB00029653"/>], as well as various exosome complex exonucleases (RRP41, RRP42, RRP43, RRP45, RRP46, MTR3, ECX1, ECX2) [<cite idref="PUB00035569"/>].</li><li>DNA modification proteins (DNA mismatch repair proteins MutL and PMS2, DNA gyrase B, DNA topoisomerase II, IV-B and VI-B) [<cite idref="PUB00024488"/>]. </li><li> GHMP kinases that transfer a phosphoryl group from ATP to an acceptor (galactokinase (<db_xref db="EC" dbkey=""/>), homoserine kinase (<db_xref db="EC" dbkey=""/>), and mevalonate kinase (<db_xref db="EC" dbkey=""/>)) [<cite idref="PUB00034482"/>, <cite idref="PUB00015644"/>].</li><li> <taxon tax_id="6239">Caenorhabditis elegans</taxon> early switch protein Xol-1 (a divergent member of the GHMP kinase family that has lost the ATP-binding site) [<cite idref="PUB00016021"/>].</li><li>Hsp90 chaperone (middle domain), which is related to the DNA gyrase/MutL family [<cite idref="PUB00035354"/>]; this domain contains an extra C-terminal alpha/beta subdomain.</li><li>Imidazole glycerol phosphate dehydratase, which contains a duplication consisting of two structural repeats of this fold [<cite idref="PUB00022600"/>].</li><li>The catalytic domain of ATP-dependent protease Lon (La), which contains an extra C-terminal alpha/beta subdomain [<cite idref="PUB00030777"/>].</li><li>Formaldehyde-activating enzyme FAE, which contains a modification of this fold consisting of an extra alpha/beta unit after strand 2 [<cite idref="PUB00038434"/>].</li></ul> Ribosomal protein S5 domain 2-type fold