| First Author | Mott HR | Year | 2003 |
| Journal | J Biol Chem | Volume | 278 |
| Issue | 19 | Pages | 17053-9 |
| PubMed ID | 12624092 | Mgi Jnum | J:83311 |
| Mgi Id | MGI:2661001 | Doi | 10.1074/jbc.M300155200 |
| Citation | Mott HR, et al. (2003) Structure of the GTPase-binding domain of Sec5 and elucidation of its Ral binding site. J Biol Chem 278(19):17053-9 |
| abstractText | The exocyst complex is involved in the final stages of exocytosis, when vesicles are targeted to the plasma membrane and dock. The regulation of exocytosis is vital for a number of processes, for example, cell polarity, embryogenesis, and neuronal growth formation. Regulation of the exocyst complex in mammals was recently shown to be dependent upon binding of the small G protein, Ral, to Sec5, a central component of the exocyst. This interaction is thought to be necessary for anchoring the exocyst to secretory vesicles. We have determined the structure of the Ral-binding domain of Sec5 and shown that it adopts a fold that has not been observed in a G protein effector before. This fold belongs to the immunoglobulin superfamily in a subclass known as IPT domains. We have mapped the Ral binding site on this domain and found that it overlaps with protein-protein interaction sites on other IPT domains but that it is completely different from the G protein-geranyl-geranyl interaction face of the Ig-like domain of the Rho guanine nucleotide dissociation inhibitor. This mapping, along with available site-directed mutagenesis data, allows us to predict how Ral and Sec5 may interact. |
