PDB ID: 1EE5
Number of Polypeptide Chains in the Protein: 2
Chain 1: A; Chain 2: B
SRP1, KAP60, YNL189W, N1606
PDB Deposition Title:
YEAST KARYOPHERIN (IMPORTIN) ALPHA IN A COMPLEX WITH A NUCLEOPLASMIN NLS PEPTIDE
Primary Citation Title:
Crystallographic analysis of the specific yet versatile recognition of distinct nuclear localization signals by karyopherin alpha.
Conti, E., Kuriyan, J.
(2000) Structure Fold.Des. 8: 329-338
Related PDB Entries:
1BK5, 1BK6, 1UN0, 1EE4, 1WA5
Information for Chain A; UniprotKB Accession Number: Q02821
Length of the Chain (from Uniprot Q02821): 542
FASTA Sequence for the chain (from Uniprot Q02821):
>sp|Q02821|IMA1_YEAST Importin subunit alpha OS=Saccharomyces cerevisiae (strain ATCC 204508 / S288c) GN=SRP1 PE=1 SV=1
Secondary Structures (DSSP defined; from RCSB PDB)
Helical Structures: Number of Helices: 35; Percentage of Residues: 73
Beta Strands: Number of Strands: 0; Percentage of Residues: 0
Secondary Structure Map:
Number of Domains Along Chain A: 1
CATH Domain IDs: 1ee5A00
CATH Classes: A00: Mainly Alpha
CATH Architectures: A00: Alpha Horseshoe
CATH Topologies: A00: Leucine-rich Repeat Variant
Function and Ligand Binding Site
Excerpt from Abstract:
Karyopherin alpha (importin alpha) is an adaptor molecule that recognizes proteins containing nuclear localization signals (NLSs). The prototypical NLS that is able to bind to karyopherin alpha is that of the SV40 T antigen, and consists of a short positively charged sequence motif. Distinct classes of NLSs (monopartite and bipartite) have been identified that are only partly conserved with respect to one another but are nevertheless recognized by the same receptor.
Description of Function from Uniprot:
Binds specifically and directly to substrates containing either a simple or bipartite NLS motif. Promotes docking of import substrates to the nuclear envelope. Seems to act as a cytosolic receptor for both simple and bipartite NLS motifs (By similarity).
Selected Molecular Function GO Terms:
GO ID: 0006606, Name: Protein import into nucleus, Definition: The directed movement of a protein from the cytoplasm to the nucleus.||
GO ID: 0008565, Name: Protein transporter activity, Definition: Enables the directed movement of proteins into, out of or within a cell, or between cells.||
GO ID: 0005515, Name: Protein binding, Definition: Interacting selectively and non-covalently with any protein or protein complex (a complex of two or more proteins that may include other nonprotein molecules).
EC Number: N/A
Major Organic Ligand: CITRATE ANION
Ligand Binding Residues:
His 261, Asn 263, Gln 297, Lys 300