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Protein Structures and Oligomeric States

Enter a protein name, UniProt accession or PDB ID. Name searches ask you to confirm the protein identity before related structures are queried.

Current Protein Identity：P03023 New Search
22PDB entries
26Biological assembly
52chain/assembly records
Main Difference Dimensions in This Set
Different construct Different mutation/modification Different assembly state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics

Difference tags compare only the current result set; every original PDB and assembly record remains separate.

Related-Structure Differences

Each row represents one biological assembly in one PDB entry; multiple monomers of the same protein are listed separately.

PDB Entry Assembly / Oligomeric State Construct Mutations and Modifications Ligands, Ions and Non-polymers Experimental Method Experimental Conditions Structure Quality
1CJG NMR STRUCTURE OF LAC REPRESSOR HP62-DNA COMPLEX Deposited 1999-04-14 Assembly 1 Protein–DNA Homooligomer；Protein × 2 PDB declaration: tetrameric（4） Consistent with all polymers
Chain A 1–62（62 aa） Fragment：HEADPIECE, RESIDUES 1 - 62
Chain B 1–62（62 aa） Fragment：HEADPIECE, RESIDUES 1 - 62
Not recorded No recorded non-water small molecule SOLUTION NMR
NMR measurement conditions pH 6.1；315 K；Ionic strength (raw mmCIF value) SEE ARTICLE；Pressure 1
NMR sample composition SEE ARTICLE
Resolution not provided
1EFA CRYSTAL STRUCTURE OF THE LAC REPRESSOR DIMER BOUND TO OPERATOR AND THE ANTI-INDUCER ONPF Deposited 2000-02-07 Assembly 1 Protein–DNA Homooligomer；Protein × 2 PDB declaration: tetrameric（4） Consistent with all polymers
Chain A 1–333（333 aa） Fragment：RESIDUES 1-333
Chain B 1–333（333 aa） Fragment：RESIDUES 1-333
Mutation：ALA109THR Mutation：ALA109THR NPF 2-nitrophenyl beta-D-fucopyranoside × 2 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 7.5；298 K；ammonium sulfate, PEG 400, HEPES, Glycerol, pH 7.5, VAPOR DIFFUSION, HANGING DROP, temperature 298.0K
Resolution 2.60 Å R-free 0.264
1EFA CRYSTAL STRUCTURE OF THE LAC REPRESSOR DIMER BOUND TO OPERATOR AND THE ANTI-INDUCER ONPF Deposited 2000-02-07 Assembly 2 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain C 1–333（333 aa） Fragment：RESIDUES 1-333
Mutation：ALA109THR NPF 2-nitrophenyl beta-D-fucopyranoside × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 7.5；298 K；ammonium sulfate, PEG 400, HEPES, Glycerol, pH 7.5, VAPOR DIFFUSION, HANGING DROP, temperature 298.0K
Resolution 2.60 Å R-free 0.264
1JWL Structure of the Dimeric lac Repressor/Operator O1/ONPF Complex Deposited 2001-09-04 Assembly 1 Protein–DNA Homooligomer；Protein × 2 PDB declaration: tetrameric（4） Consistent with all polymers
Chain A 1–333（333 aa） Fragment：C-terminal deletion mutant
Chain B 1–333（333 aa） Fragment：C-terminal deletion mutant
Not recorded NPF 2-nitrophenyl beta-D-fucopyranoside × 2 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 7.5；295 K；ammonium sulfate, PEG400, HEPES, pH 7.5, VAPOR DIFFUSION, HANGING DROP, temperature 295K
Resolution 4.00 Å R-free 0.261
1JWL Structure of the Dimeric lac Repressor/Operator O1/ONPF Complex Deposited 2001-09-04 Assembly 2 Protein homooligomer Homooligomer；Protein × 2 PDB declaration: dimeric（2） Consistent with protein count
Chain C 1–333（333 aa） Fragment：C-terminal deletion mutant
Not recorded NPF 2-nitrophenyl beta-D-fucopyranoside × 2 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 7.5；295 K；ammonium sulfate, PEG400, HEPES, pH 7.5, VAPOR DIFFUSION, HANGING DROP, temperature 295K
Resolution 4.00 Å R-free 0.261
1JYE Structure of a Dimeric Lac Repressor with C-terminal Deletion and K84L Substitution Deposited 2001-09-12 Assembly 1 Protein homooligomer Homooligomer；Protein × 2 PDB declaration: dimeric（2） Consistent with protein count
Chain A 1–349（349 aa） Fragment：C-TERMINAL DELETION MUTANT
Mutation：YES GOL GLYCEROL × 2 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.6；295 K；Sodium Acetate, Sodium Citrate, pH 5.6, VAPOR DIFFUSION, HANGING DROP, temperature 295K
Resolution 1.70 Å R-free 0.241
1JYF Structure of the Dimeric Lac Repressor with an 11-residue C-terminal Deletion. Deposited 2001-09-12 Assembly 1 Protein homooligomer Homooligomer；Protein × 2 PDB declaration: dimeric（2） Consistent with protein count
Chain A 1–349（349 aa） Fragment：C-TERMINAL DELETION
Not recorded GOL GLYCEROL × 2 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.6；295 K；Sodium Citrate, Sodium Acetate, pH 5.6, VAPOR DIFFUSION, HANGING DROP, temperature 295K
Resolution 3.00 Å R-free 0.252
1L1M SOLUTION STRUCTURE OF A DIMER OF LAC REPRESSOR DNA-BINDING DOMAIN COMPLEXED TO ITS NATURAL OPERATOR O1 Deposited 2002-02-19 Assembly 1 Protein–DNA Homooligomer；Protein × 2 PDB declaration: tetrameric（4） Consistent with all polymers
Chain A 1–62（62 aa） Fragment：N-terminal DNA-binding domain, Residues 1-62
Chain B 1–62（62 aa） Fragment：N-terminal DNA-binding domain, Residues 1-62
Mutation：V52C Mutation：V52C No recorded non-water small molecule SOLUTION NMR
NMR measurement conditions pH 6；315 K；Ionic strength (raw mmCIF value) 10mM KPi, 20mM KCl；Pressure ambient
NMR sample composition 2mM Lac-HP62-V52C U-15N,13C, 10mM KPi, 20mM KCl, 90% H2O, 10% D2O | 90% H2O/10% D2O
Resolution not provided
1LBG LACTOSE OPERON REPRESSOR BOUND TO 21-BASE PAIR SYMMETRIC OPERATOR DNA, ALPHA CARBONS ONLY Deposited 1996-01-03 Assembly 1 Protein–DNA Homooligomer；Protein × 2 PDB declaration: tetrameric（4） Consistent with all polymers
Chain A 1–360（360 aa）
Chain B 1–360（360 aa）
Not recorded No recorded non-water small molecule X-RAY DIFFRACTION mmCIF provides none of the parsed conditions Resolution 4.80 Å
1LBG LACTOSE OPERON REPRESSOR BOUND TO 21-BASE PAIR SYMMETRIC OPERATOR DNA, ALPHA CARBONS ONLY Deposited 1996-01-03 Assembly 2 Protein–DNA Homooligomer；Protein × 2 PDB declaration: tetrameric（4） Consistent with all polymers
Chain C 1–360（360 aa）
Chain D 1–360（360 aa）
Not recorded No recorded non-water small molecule X-RAY DIFFRACTION mmCIF provides none of the parsed conditions Resolution 4.80 Å
1LBH INTACT LACTOSE OPERON REPRESSOR WITH GRATUITOUS INDUCER IPTG Deposited 1996-02-17 Assembly 1 Protein homooligomer Homooligomer；Protein × 4 PDB declaration: tetrameric（4） Consistent with protein count
Chain A 1–360（360 aa）
Chain B 1–360（360 aa）
Chain C 1–360（360 aa）
Chain D 1–360（360 aa）
Not recorded IPT 1-methylethyl 1-thio-beta-D-galactopyranoside × 4 X-RAY DIFFRACTION mmCIF provides none of the parsed conditions Resolution 3.20 Å
1LBI LAC REPRESSOR Deposited 1996-02-17 Assembly 1 Protein homooligomer Homooligomer；Protein × 4 PDB declaration: tetrameric（4） Consistent with protein count
Chain A 1–360（360 aa）
Chain B 1–360（360 aa）
Chain C 1–360（360 aa）
Chain D 1–360（360 aa）
Not recorded No recorded non-water small molecule X-RAY DIFFRACTION mmCIF provides none of the parsed conditions Resolution 2.70 Å
1LCC STRUCTURE OF THE COMPLEX OF LAC REPRESSOR HEADPIECE AND AN 11 BASE-PAIR HALF-OPERATOR DETERMINED BY NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY AND RESTRAINED MOLECULAR DYNAMICS Deposited 1993-03-25 Assembly 1 Protein–DNA Monomer；Protein × 1 PDB declaration: trimeric（3） Consistent with all polymers
Chain A 1–51（51 aa）
Not recorded NA SODIUM ION × 1 SOLUTION NMR mmCIF provides none of the parsed conditions Resolution not provided
1LCD STRUCTURE OF THE COMPLEX OF LAC REPRESSOR HEADPIECE AND AN 11 BASE-PAIR HALF-OPERATOR DETERMINED BY NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY AND RESTRAINED MOLECULAR DYNAMICS Deposited 1993-03-25 Assembly 1 Protein–DNA Monomer；Protein × 1 PDB declaration: trimeric（3） Consistent with all polymers
Chain A 1–51（51 aa）
Not recorded NA SODIUM ION × 1 SOLUTION NMR mmCIF provides none of the parsed conditions Resolution not provided
1LQC LAC REPRESSOR HEADPIECE (RESIDUES 1-56), NMR, 32 STRUCTURES Deposited 1996-08-13 Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
Chain A 1–56（56 aa） Fragment：HEADPIECE, RESIDUES 1 - 56
Not recorded No recorded non-water small molecule SOLUTION NMR mmCIF provides none of the parsed conditions Resolution not provided
1OSL Solution structure of a dimeric lactose DNA-binding domain complexed to a nonspecific DNA sequence Deposited 2003-03-20 Assembly 1 Protein–DNA Homooligomer；Protein × 2 PDB declaration: tetrameric（4） Consistent with all polymers
Chain A 1–62（62 aa） Fragment：N-terminal DNA-binding domain, residues 1-62
Chain B 1–62（62 aa） Fragment：N-terminal DNA-binding domain, residues 1-62
Mutation：V52C Mutation：V52C No recorded non-water small molecule SOLUTION NMR
NMR measurement conditions pH 5.8；300 K；Ionic strength (raw mmCIF value) 400mM KCl, 60mM KPi；Pressure ambient
NMR sample composition 2mM LAC-HP62-V52C U-15N,13C, 60mM KPI, 400mM KCL | 90% H2O/10% D2O
Resolution not provided
1TLF UNPRECEDENTED QUATERNARY STRUCTURE OF E. COLI LAC REPRESSOR CORE TETRAMER: IMPLICATIONS FOR DNA LOOPING Deposited 1995-03-06 Assembly 1 Protein homooligomer Homooligomer；Protein × 4 PDB declaration: tetrameric（4） Consistent with protein count
Chain A 19–319（301 aa）
Chain B 19–319（301 aa）
Chain C 19–319（301 aa）
Chain D 19–319（301 aa）
Not recorded EMC ETHYL MERCURY ION × 4 IPT 1-methylethyl 1-thio-beta-D-galactopyranoside × 4 X-RAY DIFFRACTION mmCIF provides none of the parsed conditions Resolution 2.60 Å
2BJC NMR structure of a protein-DNA complex of an altered specificity mutant of the lac repressor headpiece that mimics the gal repressor Deposited 2005-02-01 Assembly 1 Protein–DNA Homooligomer；Protein × 2 PDB declaration: tetrameric（4） Consistent with all polymers
Chain A 1–62（62 aa） Fragment：DNA BINDING DOMAIN, LAC HEADPIECE RESIDUES 1-62
Chain B 1–62（62 aa） Fragment：DNA BINDING DOMAIN, LAC HEADPIECE RESIDUES 1-62
Mutation：YES Mutation：YES No recorded non-water small molecule SOLUTION NMR
NMR measurement conditions pH 6；315 K；Ionic strength (raw mmCIF value) 20；Pressure 1.0
NMR sample composition 95% WATER/5% D2O
Resolution not provided
2KEI Refined Solution Structure of a Dimer of LAC repressor DNA-Binding domain complexed to its natural operator O1 Deposited 2009-01-30 Assembly 1 Protein–DNA Homooligomer；Protein × 2 PDB declaration: tetrameric（4） Consistent with all polymers
Chain A 1–62（62 aa） Fragment：UNP residues 1-62
Chain B 1–62（62 aa） Fragment：UNP residues 1-62
Mutation：V52C Mutation：V52C No recorded non-water small molecule SOLUTION NMR
NMR measurement conditions pH 6；315 K；Ionic strength (raw mmCIF value) 0.03；Pressure ambient
NMR sample composition 2 mM DNA (5'-D(*DGP*DAP*DAP*DTP*DTP*DGP*DTP*DGP*DAP*DGP*DCP*DGP*DGP*DAP*DTP*DAP*DAP*DCP*DAP*DAP*DTP*DTP*DT)-3'), 2 mM DNA (5'-D(P*DAP*DAP*DAP*DTP*DTP*DGP*DTP*DTP*DAP*DTP*DCP*DCP*DGP*DCP*DTP*DCP*DAP*DCP*DAP*DAP*DTP*DTP*DC)-3'), 2 mM Lac headpiece dimer, 10% D2O, 10 mM potassium phosphate, 20 mM potassium chloride, 90% H2O/10% D2O | 90% H2O/10% D2O
Resolution not provided
2KEJ Solution structure of a dimer of LAC repressor DNA-binding domain complexed to its natural operator O2 Deposited 2009-01-30 Assembly 1 Protein–DNA Homooligomer；Protein × 2 PDB declaration: tetrameric（4） Consistent with all polymers
Chain A 1–62（62 aa） Fragment：UNP residues 1-62
Chain B 1–62（62 aa） Fragment：UNP residues 1-62
Mutation：V52C Mutation：V52C No recorded non-water small molecule SOLUTION NMR
NMR measurement conditions pH 6；315 K；Ionic strength (raw mmCIF value) 0.03；Pressure ambient
NMR sample composition 0.7 mM DNA (5'-D(*DGP*DAP*DAP*DTP*DTP*DGP*DTP*DGP*DAP*DGP*DCP*DGP*DGP*DAP*DTP*DAP*DAP*DCP*DAP*DAP*DTP*DTP*DT)'), 0.7 mM DNA (5'-D(P*DAP*DAP*DAP*DTP*DTP*DGP*DTP*DTP*DAP*DTP*DCP*DCP*DGP*DCP*DTP*DCP*DAP*DCP*DAP*DAP*DTP*DTP*DC)'), 0.7 mM Lac headpiece dimer, 5% D2O, 10 mM potassium phosphate, 20 mM potassium chloride, 5% U-100% 2H d8-glycerol, 0.01% sodium azide, 95% H2O/5% D2O | 95% H2O/5% D2O
Resolution not provided
2KEK Solution structure of a dimer of LAC repressor DNA-binding domain complexed to its natural operator O3 Deposited 2009-01-30 Assembly 1 Protein–DNA Homooligomer；Protein × 2 PDB declaration: tetrameric（4） Consistent with all polymers
Chain A 1–62（62 aa） Fragment：UNP residues 1-62
Chain B 1–62（62 aa） Fragment：UNP residues 1-62
Mutation：V52C Mutation：V52C No recorded non-water small molecule SOLUTION NMR
NMR measurement conditions pH 6；315 K；Ionic strength (raw mmCIF value) 0.03；Pressure ambient
NMR sample composition 0.7 mM DNA (5'-strand1-3'), 0.7 mM DNA (5'-strand2-3'), 0.7 mM Lac headpiece dimer, 5% D2O, 10 mM potassium phosphate, 20 mM potassium chloride, 5% U-100% 2H d8-glycerol, 0.01% sodium azide, 95% H2O/5% D2O | 95% H2O/5% D2O
Resolution not provided
2P9H High resolution structure of the Lactose Repressor bound to IPTG Deposited 2007-03-26 Assembly 1 Protein homooligomer Homooligomer；Protein × 2 PDB declaration: dimeric（2） Consistent with protein count
Chain A 62–330（269 aa）
Chain B 62–330（269 aa）
Not recorded IPT 1-methylethyl 1-thio-beta-D-galactopyranoside × 2 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.6；281 K；1.4 M Sodium Acetate, 0.1 M Sodium Citrate, pH 5.6, VAPOR DIFFUSION, HANGING DROP, temperature 281K
Resolution 2.00 Å R-free 0.246
2PAF Crystal Structure of the Lactose Repressor bound to anti-inducer ONPF in induced state Deposited 2007-03-27 Assembly 1 Protein homooligomer Homooligomer；Protein × 2 PDB declaration: dimeric（2） Consistent with protein count
Chain A 62–330（269 aa）
Chain B 62–330（269 aa）
Not recorded NPF 2-nitrophenyl beta-D-fucopyranoside × 2 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.6；281 K；1.4 M Sodium Acetate, 0.1 M Sodium Citrate, pH 5.6, VAPOR DIFFUSION, HANGING DROP, temperature 281K
Resolution 3.50 Å R-free 0.265
2PE5 Crystal Structure of the Lac Repressor bound to ONPG in repressed state Deposited 2007-04-02 Assembly 1 Protein–DNA Homooligomer；Protein × 2 PDB declaration: tetrameric（4） Consistent with all polymers
Chain A 2–331（330 aa） Fragment：sequence database residues 2-331
Chain B 2–331（330 aa） Fragment：sequence database residues 2-331
Mutation：S61L Mutation：S61L 145 2-nitrophenyl beta-D-galactopyranoside × 2 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 7.5；281 K；1.8 M Ammonium Sulfate, 0.1 M Hepes pH 7.5. 11% PEG 400, 14% glycerol, 10X ONPG, VAPOR DIFFUSION, HANGING DROP, temperature 281K
Resolution 3.50 Å R-free 0.287
2PE5 Crystal Structure of the Lac Repressor bound to ONPG in repressed state Deposited 2007-04-02 Assembly 2 Protein–DNA Homooligomer；Protein × 2 PDB declaration: tetrameric（4） Consistent with all polymers
Chain C 2–331（330 aa） Fragment：sequence database residues 2-331
Mutation：S61L 145 2-nitrophenyl beta-D-galactopyranoside × 2 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 7.5；281 K；1.8 M Ammonium Sulfate, 0.1 M Hepes pH 7.5. 11% PEG 400, 14% glycerol, 10X ONPG, VAPOR DIFFUSION, HANGING DROP, temperature 281K
Resolution 3.50 Å R-free 0.287
3EDC Crystal Structure of a 1.6-hexanediol Bound Tetrameric Form of Escherichia coli Lac-repressor Refined to 2.1 Resolution Deposited 2008-09-03 Assembly 1 Protein homooligomer Homooligomer；Protein × 4 PDB declaration: tetrameric（4） Consistent with protein count
Chain A 1–360（360 aa）
Chain B 1–360（360 aa）
Chain C 1–360（360 aa）
Chain D 1–360（360 aa）
Not recorded HEZ HEXANE-1,6-DIOL × 4 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 7.5；294 K；microseeded, pH 7.5, VAPOR DIFFUSION, HANGING DROP, temperature 294K
Resolution 2.10 Å R-free 0.201

This page presents structural evidence recorded in PDB/mmCIF.“No recorded non-water small molecule” does not prove that the experimental sample was ligand-free; experimental conditions belong to the PDB experiment, while ligands and copy counts are shown for each biological assembly.