3L3Q

Mouse importin alpha-pepTM NLS peptide complex

3L3Q の概要

• エントリーDOI: 10.2210/pdb3l3q/pdb
• 関連するPDBエントリー: 1EJL 1EJY 1IAL 1IQ1 1PJM 1PJN 1Q1S 1Q1T
• 分子名称: Importin subunit alpha-2, pepTM, CITRATE ANION, ... (4 entities in total)
• 機能のキーワード: armadillo repeats, protein transport
• 由来する生物種: Mus musculus (mouse); 詳細
• 細胞内の位置: Cytoplasm (By similarity): P52293
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 50063.11

構造登録者

Takeda, A.A.S.,Kobe, B.,Fontes, M.R.M. (登録日: 2009-12-17, 公開日: 2010-04-07, 最終更新日: 2023-11-01)

主引用文献

Yang, S.N.Y.,Takeda, A.A.S.,Fontes, M.R.M.,Harris, J.M.,Jans, D.A.,Kobe, B.
Probing the specificity of binding to the major nuclear localization sequence-binding site of importin-alpha using oriented peptide library screening.
J.Biol.Chem., 285:19935-19946, 2010

PubMed Abstract: Importin-alpha is the nuclear import receptor that recognizes the classic monopartite and bipartite nuclear localization sequences (cNLSs), which contain one or two clusters of basic amino acids, respectively. Different importin-alpha paralogs in a single organism are specific for distinct repertoires of cargos. Structural studies revealed that monopartite cNLSs and the C-terminal basic clusters of the bipartite cNLSs bind to the same site on importin-alpha, termed the major cNLS-binding site. We used an oriented peptide library approach with five degenerate positions to probe the specificity of the major cNLS-binding site in importin-alpha. We identified the sequences KKKRR, KKKRK, and KKRKK as the optimal sequences for binding to this site for mouse importin-alpha2, human importin-alpha1, and human importin-alpha5, respectively. The crystal structure of mouse importin-alpha2 with its optimal peptide confirmed the expected binding mode resembling the binding of simian virus 40 large tumor-antigen cNLS. Binding assays confirmed that the peptides containing these sequences bound to the corresponding proteins with low nanomolar affinities. Nuclear import assays showed that the sequences acted as functional cNLSs, with specificity for particular importin-alphas. This is the first time that structural information has been linked to an oriented peptide library screening approach for importin-alpha; the results will contribute to understanding of the sequence determinants of cNLSs, and may help identify as yet unidentified cNLSs in novel proteins.

PubMed: 20406804
DOI: 10.1074/jbc.M109.079574

実験手法

X-RAY DIFFRACTION (2.3 Å)