3ZIO

minor-site specific NLS (A28)

Summary for 3ZIO

• Entry DOI: 10.2210/pdb3zio/pdb
• Related: 3ZIN 3ZIP 3ZIQ 3ZIR
• Descriptor: IMPORTIN SUBUNIT ALPHA-2, A28NLS (3 entities in total)
• Functional Keywords: transport protein
• Biological source: MUS MUSCULUS (HOUSE MOUSE); More
• Cellular location: Cytoplasm (By similarity): P52293
• Total number of polymer chains: 3
• Total formula weight: 52499.90

Authors

Chang, C.-W.,Counago, R.M.,Williams, S.J.,Kobe, B. (deposition date: 2013-01-10, release date: 2013-08-21, Last modification date: 2023-12-20)

Primary citation

Chang, C.-W.,Counago, R.M.,Williams, S.J.,Boden, M.,Kobe, B.
Distinctive Conformation of Minor Site-Specific Nuclear Localization Signals Bound to Importin-Alpha
Traffic, 14:1144-, 2013

PubMed Abstract: Nuclear localization signals (NLSs) contain one or two clusters of basic residues and are recognized by the import receptor importin-α. There are two NLS-binding sites (major and minor) on importin-α and the major NLS-binding site is considered to be the primary binding site. Here, we used crystallographic and biochemical methods to investigate the binding between importin-α and predicted 'minor site-specific' NLSs: four peptide library-derived peptides, and the NLS from mouse RNA helicase II/Guα. The crystal structures reveal that these atypical NLSs indeed preferentially bind to the minor NLS-binding site. Unlike previously characterized NLSs, the C-terminal residues of these NLSs form an α-helical turn, stabilized by internal H-bond and cation-π interactions between the aromatic residues from the NLSs and the positively charged residues from importin-α. This helical turn sterically hinders binding at the major NLS-binding site, explaining the minor-site preference. Our data suggest the sequence RXXKR[K/X][F/Y/W]XXAF as the optimal minor NLS-binding site-specific motif, which may help identify novel proteins with atypical NLSs.

PubMed: 23910026
DOI: 10.1111/TRA.12098

Experimental method

X-RAY DIFFRACTION (2.1 Å)