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1ukl

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Revision as of 12:44, 1 January 2020

Crystal structure of Importin-beta and SREBP-2 complex

Structural highlights

1ukl is a 6 chain structure with sequence from Human and Lk3 transgenic mice. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
NonStd Res:
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[IMB1_MOUSE] Functions in nuclear protein import, either in association with an adapter protein, like an importin-alpha subunit, which binds to nuclear localization signals (NLS) in cargo substrates, or by acting as autonomous nuclear transport receptor. Acting autonomously, serves itself as NLS receptor. Docking of the importin/substrate complex to the nuclear pore complex (NPC) is mediated by KPNB1 through binding to nucleoporin FxFG repeats and the complex is subsequently translocated through the pore by an energy requiring, Ran-dependent mechanism. At the nucleoplasmic side of the NPC, Ran binds to importin-beta and the three components separate and importin-alpha and -beta are re-exported from the nucleus to the cytoplasm where GTP hydrolysis releases Ran from importin. The directionality of nuclear import is thought to be conferred by an asymmetric distribution of the GTP- and GDP-bound forms of Ran between the cytoplasm and nucleus. Mediates autonomously the nuclear import of ribosomal proteins RPL23A, RPS7 and RPL5. Binds to a beta-like import receptor binding (BIB) domain of RPL23A. In association with IPO7 mediates the nuclear import of H1 histone. In vitro, mediates nuclear import of H2A, H2B, H3 and H4 histones. In case of HIV-1 infection, binds and mediates the nuclear import of HIV-1 Rev. Imports PRKCI into the nucleus (By similarity).^[1] [SRBP2_HUMAN] Transcriptional activator required for lipid homeostasis. Regulates transcription of the LDL receptor gene as well as the cholesterol and to a lesser degree the fatty acid synthesis pathway (By similarity). Binds the sterol regulatory element 1 (SRE-1) (5'-ATCACCCCAC-3') found in the flanking region of the LDRL and HMG-CoA synthase genes.

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

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.

The structure of importin-beta bound to SREBP-2: nuclear import of a transcription factor.,Lee SJ, Sekimoto T, Yamashita E, Nagoshi E, Nakagawa A, Imamoto N, Yoshimura M, Sakai H, Chong KT, Tsukihara T, Yoneda Y Science. 2003 Nov 28;302(5650):1571-5. PMID:14645851^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Muhlhausser P, Muller EC, Otto A, Kutay U. Multiple pathways contribute to nuclear import of core histones. EMBO Rep. 2001 Aug;2(8):690-6. PMID:11493596 doi:http://dx.doi.org/10.1093/embo-reports/kve168
↑ Lee SJ, Sekimoto T, Yamashita E, Nagoshi E, Nakagawa A, Imamoto N, Yoshimura M, Sakai H, Chong KT, Tsukihara T, Yoneda Y. The structure of importin-beta bound to SREBP-2: nuclear import of a transcription factor. Science. 2003 Nov 28;302(5650):1571-5. PMID:14645851 doi:10.1126/science.1088372

1 Structural highlights
2 Function
3 Evolutionary Conservation
4 Publication Abstract from PubMed
5 See Also
6 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1ukl"

@@ Line 1: / Line 1: @@
 ==Crystal structure of Importin-beta and SREBP-2 complex==
-<StructureSection load='1ukl' size='340' side='right' caption='[[1ukl]], [[Resolution|resolution]] 3.00&Aring;' scene=''>
+<StructureSection load='1ukl' size='340' side='right'caption='[[1ukl]], [[Resolution|resolution]] 3.00&Aring;' scene=''>
 == Structural highlights ==
 <table><tr><td colspan='2'>[[1ukl]] is a 6 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human] and [http://en.wikipedia.org/wiki/Lk3_transgenic_mice Lk3 transgenic mice]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1UKL OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1UKL FirstGlance]. <br>
@@ Line 30: / Line 30: @@
 ==See Also==
-*[[Importin|Importin]]
+*[[Importin 3D structures|Importin 3D structures]]
 == References ==
 <references/>
@@ Line 36: / Line 36: @@
 </StructureSection>
 [[Category: Human]]
+[[Category: Large Structures]]
 [[Category: Lk3 transgenic mice]]
 [[Category: Imamoto, N]]

1ukl

From Proteopedia

Revision as of 12:44, 1 January 2020

Crystal structure of Importin-beta and SREBP-2 complex

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

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