9UPB: Human TREX-2

Structure of the human TREX-2 bound to UAP56. Determined by electron microscopy at 3.41 Å resolution. Released 18 Feb 2026.

Method: Electron microscopy
Resolution: 3.41 Å
Organism: Homo sapiens
Chains: 4
Atoms: 8,266
Mol. weight: 161.99 kDa
Ligands: ANP
Released: 18 Feb 2026

Explore 9UPB in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

9UPB contains 59 α-helices and 20 β-strands across 4 chains. Residue ranges use author residue numbering, as in the PDB file, from PDBe. To see them in 3D, choose the Cartoon representation with Secondary structure coloring: helices, sheets and coils get different colors.

Chain A: 22 helices, 3 β-strands

Element	Residues	Length	Sheet
α-helix	643-652	10
α-helix	661	1
α-helix	688-690	3
α-helix	694-703	10
α-helix	704-709	6
α-helix	716-737	22
α-helix	742-761	20
α-helix	762-764	3
α-helix	772-794	23
α-helix	803-813	11
α-helix	820-826	7
α-helix	829-832	4
α-helix	835-848	14
α-helix	852-861	10
α-helix	864-871	8
α-helix	874-889	16
β-strand	897-900	4	1
α-helix	901-908	8
α-helix	913-922	10
β-strand	927	1	1
β-strand	931-934	4	1
α-helix	936-938	3
α-helix	945-946	2
α-helix	952-956	5
α-helix	962-967	6

Chain B: 24 helices, 5 β-strands

Element	Residues	Length	Sheet
α-helix	6-19	14
α-helix	22-29	8
α-helix	34-36	3
α-helix	47-53	7
α-helix	58-71	14
α-helix	77-97	21
α-helix	105-126	22
α-helix	137-154	18
α-helix	168-182	15
α-helix	185-187	3
α-helix	188-197	10
α-helix	206-222	17
α-helix	226-239	14
β-strand	241	1	2
α-helix	245-260	16
β-strand	265-266	2	3
α-helix	267	1
α-helix	268-273	6
α-helix	280-286	7
α-helix	291-300	10
α-helix	302-307	6
α-helix	311-314	4
α-helix	315-317	3
α-helix	318-333	16
β-strand	337-339	3	4
α-helix	340-349	10
α-helix	357-370	14
β-strand	375-376	2	4
β-strand	383-386	4	4

Chain C: 2 helices, 2 β-strands

Element	Residues	Length	Sheet
α-helix	20-22	3
β-strand	32	1	2
β-strand	39-40	2	3
α-helix	51-62	12

Chain D: 11 helices, 10 β-strands

Element	Residues	Length	Sheet
α-helix	47-50	4
α-helix	54-63	10
α-helix	70-81	12
β-strand	87-88	2	5
α-helix	95-105	11
β-strand	116-118	3	6
α-helix	123-136	14
α-helix	137-139	3
β-strand	147-148	2	7
α-helix	154-162	9
β-strand	168	1	6
β-strand	170-171	2	7
α-helix	173-182	10
β-strand	192-194	3	6
β-strand	195	1	8
α-helix	198-203	6
α-helix	205-217	13
β-strand	223	1	6
β-strand	226	1	8
β-strand	227-228	2	5
α-helix	235-240	6

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Germinal-center associated nuclear protein	A	protein	463	Homo sapiens	O60318 (AlphaFold model)
PCI domain-containing protein 2	B	protein	426	Homo sapiens	Q5JVF3 (AlphaFold model)
26S proteasome complex subunit SEM1	C	protein	70	Homo sapiens	P60896 (AlphaFold model)
Spliceosome RNA helicase DDX39B	D	protein	455	Homo sapiens	Q13838 (AlphaFold model)

Sequence of entity 1 (A), FASTA

>9UPB_1 Germinal-center associated nuclear protein (chains A)
SAWSHPQFEKGGGSGGGSGGSAWSHPQFEKGGGGSDEVDAAAEGSEGLGPCVLSLSTLIG
TVAETSKEKYRLLDQRDRIMRQARVKRTDLDKARTFVGTCLDMCPEKERYMRETRSQLSV
FEVVPGTDQVDHAAAVKEYSRSSADQEEPLPHELRPLPVLSRTMDYLVTQIMDQKEGSLR
DWYDFVWNRTRGIRKDITQQHLCDPLTVSLIEKCTRFHIHCAHFMCEEPMSSFDAKINNE
NMTKCLQSLKEMYQDLRNKGVFCASEAEFQGYNVLLSLNKGDILREVQQFHPAVRNSSEV
KFAVQAFAALNSNNFVRFFKLVQSASYLNACLLHCYFSQIRKDALRALNFAYTVSTQRST
IFPLDGVVRMLLFRDCEEATDFLTCHGLTVSDGCVELNRSAFLEPEGLSKTRKSVFITRK
LTVSVGEIVNGGPLPPVPRHTPVCSFNSQNKYIGESLAAELPV

Sequence of entity 2 (B), FASTA

>9UPB_2 PCI domain-containing protein 2 (chains B)
DYKDHDGDYKDHDIDYKDDDDKGSAAAMAHITINQYLQQVYEAIDSRDGASCAELVSFKH
PHVANPRLQMASPEEKCQQVLEPPYDEMFAAHLRCTYAVGNHDFIEAYKCQTVIVQSFLR
AFQAHKEENWALPVMYAVALDLRVFANNADQQLVKKGKSKVGDMLEKAAELLMSCFRVCA
SDTRAGIEDSKKWGMLFLVNQLFKIYFKINKLHLCKPLIRAIDSSNLKDDYSTAQRVTYK
YYVGRKAMFDSDFKQAEEYLSFAFEHCHRSSQKNKRMILIYLLPVKMLLGHMPTVELLKK
YHLMQFAEVTRAVSEGNLLLLHEALAKHEAFFIRCGIFLILEKLKIITYRNLFKKVYLLL
KTHQLSLDAFLVALKFMQVEDVDIDEVQCILANLIYMGHVKGYISHQHQKLVVSKQNPFP
PLSTVC

Sequence of entity 3 (C), FASTA

>9UPB_3 26S proteasome complex subunit SEM1 (chains C)
MSEKKQPVDLGLLEEDDEFEEFPAEDWAGLDEDEDAHVWEDNWDDDNVEDDFSNQLRAEL
EKHGYKMETS

Sequence of entity 4 (D), FASTA

>9UPB_4 Spliceosome RNA helicase DDX39B (chains D)
DYKDHDGDYKDHDIDYKDDDDKGSAAAMAENDVDNELLDYEDDEVETAAGGDGAEAPAKK
DVKGSYVSIHSSGFRDFLLKPELLRAIVDCGFEHPSEVQHECIPQAILGMDVLCQAKSGM
GKTAVFVLATLQQLEPVTGQVSVLVMCHTRELAFQISKEYERFSKYMPNVKVAVFFGGLS
IKKDEEVLKKNCPHIVVGTPGRILALARNKSLNLKHIKHFILDECDKMLEQLDMRRDVQE
IFRMTPHEKQVMMFSATLSKEIRPVCRKFMQDPMEIFVDDETKLTLHGLQQYYVKLKDNE
KNRKLFDLLDVLEFNQVVIFVKSVQRCIALAQLLVEQNFPAIAIHRGMPQEERLSRYQQF
KDFQRRILVATNLFGRGMDIERVNIAFNYDMPEDSDTYLHRVARAGRFGTKGLAITFVSD
ENDAKILNDVQDRFEVNISELPDEIDISSYIEQTR

Ligands and cofactors

ID	Name	Formula	Copies
ANP	Phosphoaminophosphonic acid-adenylate ester	C10 H17 N6 O12 P3	1

Primary citation

Molecular insights into mRNA export regulation by the human TREX-2 complex. Gong, X., Tao, R., Ge, X. et al. Nat Commun (2026) 17. DOI 10.1038/s41467-026-70088-w · PubMed

Other PDB entries of the same protein (UniProt O60318 (AlphaFold model), which also has an AlphaFold model), best resolution first:

4DHX 2.1 Å, ENY2:GANP complex
9DLP 2.79 Å, Cryo-EM structure of human TREX-2 complex bound to DDX39B(UAP56)
9T6N 3.0 Å, Cryo-EM structure of the human GANP-PCID2-DSS1 complex bound to UAP56
9UPC 3.14 Å, Structure of human TREX-2
8R7J 3.5 Å, Cryo-EM structure of the human TREX-2 complex
8R7K 3.5 Å, Cryo-EM structure of the human UAP56 - TREX-2 complex

Browse structure collections

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