<p>A widespread family of GTP-binding proteins has been recently characterised[<cite idref="PUB00000217"/>, <cite idref="PUB00001824"/>]. The function of the proteins that belong to this family is not yet known. They are polypeptides of about 40 to 48 kDa which contain the five small sequenceelements characteristic of GTP-binding proteins [<cite idref="PUB00004087"/>]. As a signature pattern wasselected the region that correspond to the ATP/GTP B motif (also called G-3 inGTP-binding proteins). </p> GTP1/OBG, conserved site