1QMA

Nuclear Transport Factor 2 (NTF2) W7A mutant

Summary for 1QMA

• Entry DOI: 10.2210/pdb1qma/pdb
• Related: 1A2K 1AR0 1ASK 1OUN
• Descriptor: NUCLEAR TRANSPORT FACTOR 2 (2 entities in total)
• Functional Keywords: transport
• Biological source: RATTUS NORVEGICUS (RAT)
• Cellular location: Cytoplasm: P13662
• Total number of polymer chains: 4
• Total formula weight: 56980.40

Authors

Bayliss, R.,Ribbeck, K.,Akin, D.,Kent, H.M.,Feldherr, C.M.,Gorlich, D.,Stewart, M.J. (deposition date: 1999-09-23, release date: 2000-02-03, Last modification date: 2023-12-13)

Primary citation

Bayliss, R.,Ribbeck, K.,Akin, D.,Kent, H.M.,Feldherr, C.M.,Gorlich, D.,Stewart, M.J.
Interaction Betweeen Ntf2 and Xfxfg-Containing Nucleoporins is Required to Mediate Nuclear Import of Ran-Gdp
J.Mol.Biol., 293:579-, 1999

PubMed Abstract: Nuclear transport factor 2 (NTF2) is a small, homodimeric protein that binds to both RanGDP and xFxFG repeat-containing nucleoporins, such as yeast Nsp1p and vertebrate p62. NTF2 is required for efficient nuclear protein import and has been shown to mediate the nuclear import of RanGDP. We have used the crystal structures of rat NTF2 and its complex with RanGDP to design a mutant, W7A-NTF2, in which the affinity for xFxFG-repeat nucleoporins is reduced while wild-type binding to RanGDP is retained. The 2.5 A resolution crystal structure of W7A-NTF2 is virtually superimposable upon the wild-type protein structure, indicating that the mutation had not introduced a more general conformational change. Therefore, our data suggest that the exposed side-chain of residue 7 is crucial to the interaction between NTF2 and xFxFG repeat-containing nucleoporins. Consistent with its reduced affinity for xFxFG nucleoporins, fluorescently labelled W7A-NTF2 binds less strongly to the nuclear envelope of permeabilized cultured cells than wild-type NTF2 and, when microinjected into Xenopus oocytes, colloidal gold coated with W7A-NTF2 binds less strongly to the central channel of nuclear pore complexes than wild-type NTF2-coated gold. Significantly, W7A-NTF2 only weakly stimulated the nuclear import of fluorescein-labelled RanGDP, providing direct evidence that an interaction between NTF2 and xFxFG repeat-containing nucleoporins is required to mediate the nuclear import of RanGDP.

PubMed: 10543952
DOI: 10.1006/JMBI.1999.3166

Experimental method

X-RAY DIFFRACTION (2.5 Å)