1UKL

Crystal structure of Importin-beta and SREBP-2 complex

Summary for 1UKL

• Entry DOI: 10.2210/pdb1ukl/pdb
• Descriptor: Importin beta-1 subunit, Sterol regulatory element binding protein-2 (2 entities in total)
• Functional Keywords: transcription factor, nuclear transport factor, heat repeat, helix-loop-helix leucine zipper, protein transport-dna binding protein complex, protein transport/dna binding protein
• Biological source: Mus musculus (house mouse); More
• Cellular location: Cytoplasm (By similarity): P70168; Endoplasmic reticulum membrane; Multi-pass membrane protein. Processed sterol regulatory element-binding protein 2: Nucleus: Q12772
• Total number of polymer chains: 6
• Total formula weight: 223652.20

Authors

Lee, S.J.,Sekimoto, T.,Yamashita, E.,Nagoshi, E.,Nakagawa, A.,Imamoto, N.,Yoshimura, M.,Sakai, H.,Tsukihara, T.,Yoneda, Y. (deposition date: 2003-08-26, release date: 2003-12-09, Last modification date: 2024-10-23)

Primary citation

Lee, S.J.,Sekimoto, T.,Yamashita, E.,Nagoshi, E.,Nakagawa, A.,Imamoto, N.,Yoshimura, M.,Sakai, H.,Chong, K.T.,Tsukihara, T.,Yoneda, Y.
The Structure of Importin-beta Bound to SREBP-2: Nuclear Import of a Transcription Factor
Science, 302:1571-1575, 2003

PubMed Abstract: 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-beta. We show the crystal structure of importin-beta complexed with the active form of SREBP-2. Importin-beta uses characteristic long helices like a pair of chopsticks to interact with an SREBP-2 dimer. Importin-beta changes its conformation to reveal a pseudo-twofold symmetry on its surface structure so that it can accommodate a symmetric dimer molecule. Importin-beta may use a similar strategy to recognize other dimeric cargoes.

PubMed: 14645851
DOI: 10.1126/science.1088372

Experimental method

X-RAY DIFFRACTION (3 Å)