PDBsum entry 5ctt

Transport protein,immune system,nuclear

PDB id: 5ctt

Contents

Protein chains

426 a.a.

16 a.a.

Waters ×472

PDB id:

5ctt

Name:

Transport protein,immune system,nuclear

Title:

Crystal structure of human sart3/tip110 nls-mouse importin alpha complex

Structure:

Importin subunit alpha-1. Chain: a. Fragment: unp residues 72-497. Synonym: importin alpha p1,karyopherin subunit alpha-2,pendulin,pore targeting complex 58 kda subunit,ptac58,rag cohort protein 1,srp1- alpha. Engineered: yes. Squamous cell carcinoma antigen recognized by t-cells 3. Chain: b.

Source:

Mus musculus. Mouse. Organism_taxid: 10090. Gene: kpna2, rch1. Expressed in: escherichia coli. Expression_system_taxid: 562. Homo sapiens. Human. Organism_taxid: 9606.

Resolution:

1.70Å R-factor: 0.192 R-free: 0.219

Authors:

J.K.Park,E.E.Kim

Key ref:

J.K.Park et al. (2016). Structural basis for recruiting and shuttling of the spliceosomal deubiquitinase USP4 by SART3. Nucleic Acids Res, 44, 5424-5437. PubMed id: 27060135 DOI: 10.1093/nar/gkw218

Date:

24-Jul-15 Release date: 27-Apr-16

Protein chain

P52293  (IMA1_MOUSE) -  Importin subunit alpha-1 from Mus musculus

Seq: 529 a.a.

Struc: 426 a.a.

Protein chain

Q15020  (SART3_HUMAN) -  Squamous cell carcinoma antigen recognized by T-cells 3 from Homo sapiens

Seq: 963 a.a.

Struc: 16 a.a.*

* PDB and UniProt seqs differ at 6 residue positions (black crosses)

DOI no: 10.1093/nar/gkw218

Nucleic Acids Res 44:5424-5437 (2016)

PubMed id: 27060135

Structural basis for recruiting and shuttling of the spliceosomal deubiquitinase USP4 by SART3.

J.K.Park, T.Das, E.J.Song, E.E.Kim.

ABSTRACT

Squamous cell carcinoma antigen recognized by T-cells 3 (SART3) is a U4/U6 recycling factor as well as a targeting factor of USP4 and USP15. However, the details of how SART3 recognizes these deubiquitinases and how they get subsequently translocated into the nucleus are not known. Here, we present the crystal structures of the SART3 half-a-tetratricopeptide (HAT) repeat domain alone and in complex with the domain present in ubiquitin-specific protease (DUSP)-ubiquitin-like (UBL) domains of ubiquitin specific protease 4 (USP4). The 12 HAT repeats of SART3 are in two sub-domains (HAT-N and HAT-C) forming a dimer through HAT-C. USP4 binds SART3 at the opposite surface of the HAT-C dimer interface utilizing the β-structured linker between the DUSP and the UBL domains. The binding affinities of USP4 and USP15 to SART3 are 0.9 μM and 0.2 μM, respectively. The complex structure of SART3 nuclear localization signal (NLS) and importin-α reveals bipartite binding, and removal of SART3 NLS prevents the entry of USP4 (and USP15) into the nucleus and abrogates the subsequent deubiquitinase activity of USP4.