High-resolution crystal structure of S. cerevisiae Ypt51(DeltaC15)-GppNHp, a small GTP-binding protein involved in regulation of endocytosis.
Esters, H., Alexandrov, K., Constantinescu, A.T., Goody, R.S., Scheidig, A.J.(2000) J Mol Biol 298: 111-121
- PubMed: 10756108 
- DOI: https://doi.org/10.1006/jmbi.2000.3645
- Primary Citation of Related Structures:  
1EK0 - PubMed Abstract: 
Ypt/Rab proteins are membrane-associated small GTP-binding proteins which play a central role in the coordination, activation and regulation of vesicle-mediated transport in eukaryotic cells. We present the 1.5 A high-resolution crystal structure of Ypt51 in its active, GppNHp-bound conformation. Ypt51 is an important regulator involved in the endocytic membrane traffic of Saccharomyces cerevisiae. The structure reveals small but significant structural differences compared with H-Ras p21. The effector loop and the catalytic loop are well defined and stabilized by extensive hydrophobic interactions. The switch I and switch II regions form a well-defined epitope for hypothetical effector protein binding. Sequence comparisons between the different isoforms Ypt51, Ypt52 and Ypt53 provide the first insights into determinants for specific effector binding and for fine-tuning of the intrinsic GTP-hydrolysis rate.
Organizational Affiliation: 
Abteilung für Physikalische Biochemie, Max-Planck Institut für molekulare Physiologie, Otto-Hahn-Strasse 11, Dortmund, 44227, Germany.