Portal de Periódicos da CAPES

The Structure of Importin-ß Bound to SREBP-2: Nuclear Import of a Transcription Factor

2003; American Association for the Advancement of Science; Volume: 302; Issue: 5650 Linguagem: Inglês

10.1126/science.1088372

1095-9203

Soo Jae Lee, Toshihiro Sekimoto, Eiki Yamashita, Emi Nagoshi, Atsushi Nakagawa, Naoko Imamoto, Masato Yoshimura, Hiroaki Sakai, Khoon Tee Chong, Tomitake Tsukihara, Yoshihiro Yoneda,

RNA and protein synthesis mechanisms

The sterol regulatory element–binding protein 2 (SREBP-2), a nuclear transcription factor that is essential for cholesterol metabolism, enters the nucleus through a direct interaction of its helix-loop-helix leucine zipper domain with importin-β. We show the crystal structure of importin-β complexed with the active form of SREBP-2. Importin-β uses characteristic long helices like a pair of chopsticks to interact with an SREBP-2 dimer. Importin-β changes its conformation to reveal a pseudo-twofold symmetry on its surface structure so that it can accommodate a symmetric dimer molecule. Importin-β may use a similar strategy to recognize other dimeric cargoes.