SASDAC5: ImportinA_ImportinB (ImpA_ImpB)

Basic information

• Entry: Database: SASBDB / ID: SASDAC5

Sample

ImportinA_ImportinB

• ImportinA_ImportinB (protein), ImpA_ImpB, Escherichia coli

• Biological species: Escherichia coli (E. coli)
• Citation: Journal: Biochemistry / Year: 2010; Title: Recognition of nucleoplasmin by its nuclear transport receptor importin α/β: insights into a complete import complex.; Authors: Jorge Falces / Igor Arregi / Petr V Konarev / María A Urbaneja / Dmitri I Svergun / Stefka G Taneva / Sonia Bañuelos / ; Abstract: Nuclear import of the pentameric histone chaperone nucleoplasmin (NP) is mediated by importin α, which recognizes its nuclear localization sequence (NLS), and importin β, which interacts with α and is in charge of the translocation of the NP/α/β complex through the nuclear pore. Herein, we characterize the assembly of a functional transport complex formed by full-length NP with importin α/β. Isothermal titration calorimetry (ITC) was used to analyze the thermodynamics of the interactions of importin α with β, α with NP, and the α/β heterodimer with NP. Our data show that binding of both importin α and α/β to NP is governed by a favorable enthalpic contribution and that NP can accommodate up to five importin molecules per NP pentamer. Phosphomimicking mutations of NP, which render the protein active in histone chaperoning, do not modulate the interaction with importin. Using small-angle X-ray scattering, we model the α/β heterodimer, NP/α, and NP/α/β solution structures, which reveal a glimpse of a complete nuclear import complex with an oligomeric cargo protein. The set of alternative models, equally well fitting the scattering data, yields asymmetric elongated particles that might represent consecutive geometries the complex can adopt when stepping through the nuclear pore.

Contact author

• Petr Konarev (EMBL-Hamburg, European Molecular Biology Laboratory (EMBL) - Hamburg outstation, Notkestraße 85, Geb. 25A, 22607 Hamburg, Deutschland, Germany)

Models

• Model #107: ; Type: dummy / Software: Dammif / Radius of dummy atoms: 6.80 A / Chi-square value: 1.252161; Search similar-shape structures of this assembly by Omokage search (details)
• Model #108: ; Type: atomic / Software: Sasref / Chi-square value: 1.4161; Search similar-shape structures of this assembly by Omokage search (details)

Sample

• Sample: Name: ImportinA_ImportinB / Sample MW: 160 kDa / Specimen concentration: 0.50-1.00
• Buffer: Name: 50 mM Tris-HCL / pH: 7.5 / Composition: 150 mM NaCl, 1.0 mM DTT

Entity #85

Name: ImpA_ImpB / Type: protein / Description: ImportinA_ImportinB / Formula weight: 160 / Num. of mol.: 1 / Source: Escherichia coli
Sequence:

VQVPPLSLEE IVQGMNSGDP ENELRCTQAA RKMLSRERNP PLNDIIEAGL IPKLVEFLSR HDNSTLQFEA AWALNIASGT SDQTKSVVDG GAIPAFISLI SSPHLHISEA VWALGNIAGD GPLYRDALIN CNVIPPLLAL VNPQTPLGYL NITWMLSNLC RNKNPYPPMS AVLQILPVLT QLMHHDDKDI LSDTCAMSYL TDGSNDRIDV VVKTGIVDRL IQLMYSPELS IVTPSLRTVG NIVTGTDKQT QAAIDAGVLS VLPQLLRHQK PSIQKEAAWA ISNIAAGPAP QIQQMITCGL LSPLVDLLNK GDFKAQKEAV WAVTNYTSGG TVEQVVQLVQ CGVLEPLLNL LTIKDSKTIL VILDAISNIF LAAEKLGEQE KLCLLVEELG GLEKIEALQT HDNHMVYHAA LALIEKYFME LITILEKTVS PDRLELEAAQ KFLERAAVEN LPTFLVELSR VLANPGNSQV ARVAAGLQIK NSLTSKDPDI KAQYQQRWLA IDANARREVK NYVLHTLGTE TYRPSSASQC VAGIACAEIP VNQWPELIPQ LVANVTNPNS TEHMKESTLE AIGYICQDID PEQLQDKSNE ILTAIIQGMR KEEPSNNVKL AATNALLNSL EFTKANFDKE SERHFIMQVV CEATQCPDTR VRVAALQNLV KIMSLYYQYM ETYMGPALFA ITIEAMKSDI DEVALQGIEF WSNVCDEEMD LAIEASEAAE QGRPPEHTSK FYAKGALQYL VPILTQTLTK QDENDDDDDW NPCKAAGVCL MLLATCCEDD IVPHVLPFIK EHIKNPDWRY RDAAVMAFGC ILEGPEPSQL KPLVIQAMPT LIELMKDPSV VVRDTAAWTV GRICELLPEA AINDVYLAPL LQCLIEGLSA EPRVASNVCW AFSSLAEAAY EAADVADDQE EPATYCLSSS FELIVQKLLE TTDRPDGHQN NLRSSAYESL MEIVKNSAKD CYPAVQKTTL VIMERLQQVL QMESHIQSTS DRIQFNDLQS LLCATLQNVL RKVQHQDALQ ISDVVMASLL RMFQSTAGSG GVQEDALMAV STLVEVLGGE FLKYMEAFKP FLGIGLKNYA EYQVCLAAVG LVGDLCRALQ SNIIPFCDEV MQLLLENLGN ENVHRSVKPQ ILSVFGDIAL AIGGEFKKYL EVVLNTLQQA SQAQVDKSDY DMVDYLNELR ESCLEAYTGI VQGLKGDQEN VHPDVMLVQP RVEFILSFID HIAGDEDHTD GVVACAAGLI GDLCTAFGKD VLKLVEARPM IHELLTEGRR SKTNKAKTLA RWATKELRKL KNQAAARLHR FKNKGKDSTE MRRRRIEVNV ELRKAKKDDQ MLKRRNVSSQ MANKEPSLIL EEPL

Experimental information

• Beam: Instrument name: DORIS III X33 / City: Hamburg / 国: Germany / Type of source: X-ray synchrotron
• Detector: Name: Pilatus 2M

Scan

Title: ImpA-ImpB / Measurement date: Oct 29, 2009 / Storage temperature: 10 °C / Cell temperature: 10 °C / Exposure time: 15 sec. / Number of frames: 8 / Unit: 1/nm /

	Min	Max
Q	0.0775	6.237

Distance distribution function P(R)

Sofotware P(R): GNOM 4.5a / Number of points: 320 /

	Min	Max
Q	0.1375	1.839
P(R) point	23	342
R	0	19

Result

Type of curve: single_conc /

	Experimental	Porod
MW	185 kDa	-
Volume	-	390 nm3

	P(R)	Guinier
Forward scattering, I0	81	80
Radius of gyration, Rg	5.7 nm	5.65 nm

	Min	Max
D	-	19
Guinier point	12	67