期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2010
卷号：107
期号：12
页码：5441-5446
DOI：10.1073/pnas.0909877107
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The eukaryotic translation initiation factor eIF4E, a potent oncogene, is highly regulated. One class of eIF4E regulators, including eIF4G and the 4E-binding proteins (4E-BPs), interact with eIF4E using a conserved YXXXXL{Phi}-binding site. The structural basis of this interaction and its regulation are well established. Really Interesting New Gene (RING) domain containing proteins, such as the promyelocytic leukemia protein PML and the arenaviral protein Z, represent a second class of eIF4E regulators that inhibit eIF4E function by decreasing eIF4E's affinity for its m7G cap ligand. To elucidate the structural basis of this inhibition, we determined the structure of Z and studied the Z-eIF4E complex using NMR methods. We show that Z interacts with eIF4E via a novel binding site, which has no homology with that of eIF4G or the 4E-BPs, and is different from the RING recognition site used in the ubiquitin system. Z and eIF4G interact with distinct parts of eIF4E and differentially alter the conformation of the m7G cap-binding site. Our results provide a molecular basis for how PML and Z RINGs reduce the affinity of eIF4E for the m7G cap and thereby act as key inhibitors of eIF4E function. Furthermore, our findings provide unique insights into RING protein interactions.
关键词：Lassa Fever Virus-Z ; NMR ; promyelocytic leukemia protein
