<p>This entry represents a structural domain consisting of a 3-layer alpha/beta/alpha fold. The beta layer is composed of seven beta-sheets, and the overall order is: (beta-hairpin)-beta(3)-alpha-beta(4)-alpha. Domains with this structure are found in the following protein families:</p><p> <ul><li>Ran-binding protein Mog1, which interacts with Ran GTPase to stimulate guanine nucleotide release, suggesting Mog1 regulates the nuclear transport functions of Ran [<cite idref="PUB00015069"/>, <cite idref="PUB00026393"/>].</li><li>The photosystem II (PSII) oxygen-evolving complex protein PsbP, which is a regulator necessary for the biogenesis of optically active PSII. PsbP increases the affinity of the water oxidation site for chloride ions and provides the conditions required for high affinity binding of calcium ions [<cite idref="PUB00015371"/>].</li><li> <db_xref db="INTERPRO" dbkey="IPR014894"/>, which are hypothetical proteins consisting of a segment-swapped dimers that have some sequence similarity to the PsbP-like family.</li></ul> </p>