9UIN: Thioredoxin reductase 1, cytoplasmic

Human thioredoxin reductase 1 (SeCys 498 Cys) with Cu(I). Determined by electron microscopy at 3.03 Å resolution. Released 22 Apr 2026.

Method: Electron microscopy
Resolution: 3.03 Å
Organism: Homo sapiens
Chains: 2
Atoms: 7,690
Mol. weight: 112.99 kDa
Ligands: FAD, CU, TXP
Released: 22 Apr 2026

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

Secondary structure: helices and β-sheets

9UIN contains 34 α-helices and 60 β-strands across 2 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: 17 helices, 30 β-strands

Element	Residues	Length	Sheet
β-strand	15-18	4	11
α-helix	22-32	11
β-strand	39-41	3	11
α-helix	45-47	3
α-helix	58-61	4
α-helix	64-82	19
α-helix	83-86	4
β-strand	88	1	3
β-strand	96	1	2
α-helix	98-122	25
β-strand	126-128	3	11
β-strand	134-136	3	12
β-strand	139-140	2	12
β-strand	152	1	12
β-strand	156-159	4	11
β-strand	163-165	3	13
β-strand	178	1	14
α-helix	180-183	4
β-strand	193-196	4	14
α-helix	200-210	11
β-strand	216-220	5	14
α-helix	230-243	14
β-strand	246-249	4	14
β-strand	251-260	10	15
β-strand	266-273	8	15
β-strand	279-284	6	15
β-strand	286-289	4	14
β-strand	293-295	3	13
α-helix	302-305	4
β-strand	316	1	16
β-strand	323	1	17
β-strand	330	1	17
β-strand	336	1	16
α-helix	343-354	12
α-helix	355-359	5
β-strand	372-374	3	18
β-strand	380-384	5	18
α-helix	388-394	7
β-strand	399-406	8	18
α-helix	409-412	4
β-strand	421-428	8	18
β-strand	434-441	8	18
α-helix	445-455	11
β-strand	461	1	18
α-helix	462-467	6
α-helix	476-481	6
β-strand	485	1	18

Chain B: 17 helices, 30 β-strands

Element	Residues	Length	Sheet
β-strand	15-18	4	1
α-helix	22-32	11
β-strand	39-41	3	1
α-helix	45-47	3
α-helix	58-61	4
α-helix	64-82	19
α-helix	83-86	4
β-strand	88	1	2
β-strand	96	1	3
α-helix	98-122	25
β-strand	126-128	3	1
β-strand	134-136	3	4
β-strand	139-140	2	4
β-strand	152	1	4
β-strand	156-159	4	1
β-strand	163-165	3	5
β-strand	178	1	6
α-helix	180-183	4
β-strand	193-196	4	6
α-helix	200-210	11
β-strand	216-220	5	6
α-helix	230-243	14
β-strand	246-249	4	6
β-strand	251-260	10	7
β-strand	266-273	8	7
β-strand	279-284	6	7
β-strand	286-289	4	6
β-strand	293-295	3	5
α-helix	302-305	4
β-strand	316	1	8
β-strand	323	1	9
β-strand	330	1	9
β-strand	336	1	8
α-helix	343-354	12
α-helix	355-359	5
β-strand	372-374	3	10
β-strand	380-384	5	10
α-helix	388-394	7
β-strand	399-406	8	10
α-helix	410-412	3
β-strand	421-428	8	10
β-strand	434-441	8	10
α-helix	445-455	11
β-strand	461	1	10
α-helix	462-467	6
α-helix	476-481	6
β-strand	485	1	10

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Thioredoxin reductase 1, cytoplasmic	A, B	protein	499	Homo sapiens	Q16881

Sequence of entity 1 (A, B), FASTA

>9UIN_1 Thioredoxin reductase 1, cytoplasmic (chains A, B)
MNGPEDLPKSYDYDLIIIGGGSGGLAAAKEAAQYGKKVMVLDFVTPTPLGTRWGLGGTCV
NVGCIPKKLMHQAALLGQALQDSRNYGWKVEETVKHDWDRMIEAVQNHIGSLNWGYRVAL
REKKVVYENAYGQFIGPHRIKATNNKGKEKIYSAERFLIATGERPRYLGIPGDKEYCISS
DDLFSLPYCPGKTLVVGASYVALECAGFLAGIGLDVTVMVRSILLRGFDQDMANKIGEHM
EEHGIKFIRQFVPIKVEQIEAGTPGRLRVVAQSTNSEEIIEGEYNTVMLAIGRDACTRKI
GLETVGVKINEKTGKIPVTDEEQTNVPYIYAIGDILEDKVELTPVAIQAGRLLAQRLYAG
STVKCDYENVPTTVFTPLEYGACGLSEEKAVEKFGEENIEVYHSYFWPLEWTIPSRDNNK
CYAKIICNTKDNERVVGFHVLGPNAGEVTQGFAAALKCGLTKKQLDSTIGIHPVCAEVFT
TLSVTKRSGASILQAGCCG

Ligands and cofactors

ID	Name	Formula	Copies
FAD	Flavin-adenine dinucleotide	C27 H33 N9 O15 P2	2
CU	Copper (II) ion	Cu	6
TXP	1,4,5,6-tetrahydronicotinamide adenine dinucleotide phosphate	C21 H32 N7 O17 P3	2

Primary citation

Crystal structure of the human thioredoxin reductase 1 (SeCys 498 Cys) with Cu(I). Wang, J. To be published.

Other PDB entries of the same protein (UniProt Q16881), best resolution first:

3QFA 2.2 Å, Crystal structure of the human thioredoxin reductase-thioredoxin complex
2ZZC 2.6 Å, Crystal structure of NADP(H):human thioredoxin reductase I
3QFB 2.6 Å, Crystal structure of the human thioredoxin reductase-thioredoxin complex
2CFY 2.7 Å, Crystal structure of human thioredoxin reductase 1
2J3N 2.8 Å, X-ray structure of human thioredoxin reductase 1
2ZZ0 2.8 Å, Crystal structure of human thioredoxin reductase I (SeCys 498 Cys)
2ZZB 3.2 Å, Crystal structure of human thioredoxin reductase I and terpyridine platinum(II)
7X1R 3.9 Å, Cryo-EM structure of human thioredoxin reductase bound by Au

Browse structure collections

About this viewer

MolViewer shows 9UIN directly in your browser with nothing to install. Switch between cartoon, ball-and-stick, spacefill and surface views, color by chain, secondary structure or B-factor, measure distances, angles and dihedrals, and share or embed the view.