Replicase polyprotein 1ab
Middle East respiratory syndrome-related coronavirus
State in the Current Structure
| Assembly | Oligomeric State | Construct | Mutations and Modifications | Ligands, Ions and Associated Components | Method and Experimental Conditions | Structure Quality |
|---|---|---|---|---|---|---|
| 1 | Protein–RNA Homooligomer Protein × 2 RNA 1 PDB declaration: trimeric(3) Consistent with all polymer counts | Chain A; UniProt 4238–4377 Chain B; UniProt 5909–6432 | Not recorded | T20P14-A RNA × 1 ZN ZINC ION × 5 MG MAGNESIUM ION × 1 | ELECTRON MICROSCOPY cryo-EM buffer:pH 7.5 cryo-EM vitrification conditions:Cryogen ETHANE | Resolution 2.88 Å |
Other States of the Same Protein in the Database
Each row is a biological assembly of the same UniProt protein in another PDB entry. The “Difference from current entry” column identifies evidence-level differences; no tag means the currently parsed fields agree.
| Other PDB | Difference from Current Entry 9YCN | Assembly / Oligomeric State | Construct | Mutations and Modifications | Ligands, Ions and Non-polymers | Method and Experimental Conditions | Structure Quality |
|---|---|---|---|---|---|---|---|
| 4WUR The crystal structure of the MERS-CoV papain-like protease (C111S) with human ubiquitin Deposited 2014-11-03 | Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics | Assembly 1 Protein heterocomplex Heteromer;Protein × 2 PDB declaration: dimeric |
Chain A
1482–1801(320 aa)
Fragment:UNP residues 1482-1801
|
Mutation:C111S | IPA ISOPROPYL ALCOHOL × 2 ZN ZINC ION × 1 |
X-RAY DIFFRACTION
X-ray crystallization conditions
VAPOR DIFFUSION, SITTING DROP;pH 4.8;291 K;22% w/v PEG 4000, 15% v/v 2-propanol, 0.1M tri-sodium citrate pH 4.8 and 10% glycerol
|
Resolution 3.16 Å R-free 0.252 |
| 8PPL MERS-CoV Nsp1 bound to the human 43S pre-initiation complex Deposited 2023-07-07 | Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics | Assembly 1 Protein–RNA Heteromer;Protein × 50 PDB declaration: 52-meric |
Chain Aj
2–193(192 aa)
|
Not recorded | ZN ZINC ION × 4 GTP GUANOSINE-5'-TRIPHOSPHATE × 1 MG MAGNESIUM ION × 116 MET METHIONINE × 1 UNX UNKNOWN LIGAND × 129 |
ELECTRON MICROSCOPY
cryo-EM buffer
pH 7.4
cryo-EM vitrification conditions
Cryogen ETHANE-PROPANE
|
Resolution 2.65 Å |
| 9INM Crystal structure of MERS main protease in complex with Bofutrelvir Deposited 2024-07-08 | Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics | Assembly 1 Protein homooligomer Homooligomer;Protein × 2 PDB declaration: dimeric |
Chain A
3248–3548(301 aa)
Chain D
3248–3548(301 aa)
|
Not recorded | FHR ~{N}-[(2~{S})-3-cyclohexyl-1-oxidanylidene-1-[[(2~{S})-1-oxidanylidene-3-[(3~{S})-2-oxidanylidenepyrrolidin-3-yl]propan-2-yl]amino]propan-2-yl]-1~{H}-indole-2-carboxamide × 2 |
X-RAY DIFFRACTION
X-ray crystallization conditions
VAPOR DIFFUSION, SITTING DROP;298 K;0.2M Sodium formate, 0.1M BICINE pH8.5 20% PEG5000
|
Resolution 2.34 Å R-free 0.275 |
| 9INM Crystal structure of MERS main protease in complex with Bofutrelvir Deposited 2024-07-08 | Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics | Assembly 2 Protein homooligomer Homooligomer;Protein × 2 PDB declaration: dimeric |
Chain B
3248–3548(301 aa)
Chain C
3248–3548(301 aa)
|
Not recorded | FHR ~{N}-[(2~{S})-3-cyclohexyl-1-oxidanylidene-1-[[(2~{S})-1-oxidanylidene-3-[(3~{S})-2-oxidanylidenepyrrolidin-3-yl]propan-2-yl]amino]propan-2-yl]-1~{H}-indole-2-carboxamide × 2 |
X-RAY DIFFRACTION
X-ray crystallization conditions
VAPOR DIFFUSION, SITTING DROP;298 K;0.2M Sodium formate, 0.1M BICINE pH8.5 20% PEG5000
|
Resolution 2.34 Å R-free 0.275 |
| 9PAC Crystal structure of MERS-CoV 3CLpro with ALG-097608 (Inhibitor 1) Deposited 2025-06-25 | Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics | Assembly 1 Protein homooligomer Homooligomer;Protein × 2 PDB declaration: dimeric |
Chain C
3248–3553(306 aa)
Chain D
3248–3553(306 aa)
|
Not recorded | A1CHF (1R,2R,3S,6S,7S)-4-[(2S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butanoyl]-10,10-difluoro-N-{(1E,2R)-1-imino-3-[(3R)-2-oxo-3,4-dihydro-2H-pyrrol-3-yl]propan-2-yl}-4-azatricyclo[5.2.1.0~2,6~]decane-3-carboxamide (non-preferred name) × 1 |
X-RAY DIFFRACTION
X-ray crystallization conditions
VAPOR DIFFUSION, SITTING DROP;277.15 K;0.2M NaCl, Sodium/Potassium Phosphate 6.2, and 18% PEG1000
|
Resolution 2.28 Å R-free 0.269 |
| 9PAC Crystal structure of MERS-CoV 3CLpro with ALG-097608 (Inhibitor 1) Deposited 2025-06-25 | Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics | Assembly 2 Protein homooligomer Homooligomer;Protein × 2 PDB declaration: dimeric |
Chain A
3248–3553(306 aa)
Chain B
3248–3553(306 aa)
|
Not recorded | A1CHF (1R,2R,3S,6S,7S)-4-[(2S)-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butanoyl]-10,10-difluoro-N-{(1E,2R)-1-imino-3-[(3R)-2-oxo-3,4-dihydro-2H-pyrrol-3-yl]propan-2-yl}-4-azatricyclo[5.2.1.0~2,6~]decane-3-carboxamide (non-preferred name) × 2 |
X-RAY DIFFRACTION
X-ray crystallization conditions
VAPOR DIFFUSION, SITTING DROP;277.15 K;0.2M NaCl, Sodium/Potassium Phosphate 6.2, and 18% PEG1000
|
Resolution 2.28 Å R-free 0.269 |
| 9PAK Crystal structure of MERS-CoV 3CLpro with ALG-097655 (Inhibitor 2) Deposited 2025-06-25 | Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics | Assembly 1 Protein homooligomer Homooligomer;Protein × 2 PDB declaration: dimeric |
Chain A
3248–3553(306 aa)
Chain B
3248–3553(306 aa)
|
Not recorded | A1CHJ (1R,2S,3S,6R,7S)-N-{(1Z,2S)-1-imino-3-[(3S)-2-oxopyrrolidin-3-yl]propan-2-yl}-4-[(2S)-4,4,4-trifluoro-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butanoyl]-4-azatricyclo[5.2.1.0~2,6~]dec-8-ene-3-carboxamide (non-preferred name) × 2 |
X-RAY DIFFRACTION
X-ray crystallization conditions
VAPOR DIFFUSION, SITTING DROP;277.15 K;0.2M NaCl, Sodium/Potassium Phosphate 6.2, and 18% PEG1000
|
Resolution 1.86 Å R-free 0.239 |
| 9PAK Crystal structure of MERS-CoV 3CLpro with ALG-097655 (Inhibitor 2) Deposited 2025-06-25 | Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics | Assembly 2 Protein homooligomer Homooligomer;Protein × 2 PDB declaration: dimeric |
Chain C
3248–3553(306 aa)
Chain D
3248–3553(306 aa)
|
Not recorded | A1CHJ (1R,2S,3S,6R,7S)-N-{(1Z,2S)-1-imino-3-[(3S)-2-oxopyrrolidin-3-yl]propan-2-yl}-4-[(2S)-4,4,4-trifluoro-3,3-dimethyl-2-(2,2,2-trifluoroacetamido)butanoyl]-4-azatricyclo[5.2.1.0~2,6~]dec-8-ene-3-carboxamide (non-preferred name) × 2 |
X-RAY DIFFRACTION
X-ray crystallization conditions
VAPOR DIFFUSION, SITTING DROP;277.15 K;0.2M NaCl, Sodium/Potassium Phosphate 6.2, and 18% PEG1000
|
Resolution 1.86 Å R-free 0.239 |
| 9XG7 The crystal structure of MERS-CoV Main protease in complex with inhibitor FD2-21 Deposited 2025-10-29 | Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics | Assembly 1 Protein homooligomer Homooligomer;Protein × 2 PDB declaration: dimeric |
Chain A
3248–3551(304 aa)
Chain B
3248–3551(304 aa)
|
Not recorded | A1EZ7 7-(5-azanylpyridin-3-yl)-2-(2-chlorophenyl)-5,7-diazaspiro[3.4]octane-6,8-dione × 2 |
X-RAY DIFFRACTION
X-ray crystallization conditions
VAPOR DIFFUSION, SITTING DROP;289.15 K;0.05 M Magnesium chloride hexahydrate, 0.1 M HEPES pH 7.5, 30% v/v Polyethylene glycol monomethyl ether 550
|
Resolution 2.53 Å R-free 0.298 |
| 9XG7 The crystal structure of MERS-CoV Main protease in complex with inhibitor FD2-21 Deposited 2025-10-29 | Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics | Assembly 2 Protein homooligomer Homooligomer;Protein × 2 PDB declaration: dimeric |
Chain C
3248–3551(304 aa)
Chain D
3248–3551(304 aa)
|
Not recorded | A1EZ7 7-(5-azanylpyridin-3-yl)-2-(2-chlorophenyl)-5,7-diazaspiro[3.4]octane-6,8-dione × 1 |
X-RAY DIFFRACTION
X-ray crystallization conditions
VAPOR DIFFUSION, SITTING DROP;289.15 K;0.05 M Magnesium chloride hexahydrate, 0.1 M HEPES pH 7.5, 30% v/v Polyethylene glycol monomethyl ether 550
|
Resolution 2.53 Å R-free 0.298 |
| 9Y8W MERS Mpro with EGT710 Deposited 2025-09-11 | Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics | Assembly 1 Protein homooligomer Homooligomer;Protein × 2 PDB declaration: dimeric |
Chain A
3248–3553(306 aa)
Chain C
3248–3553(306 aa)
|
Not recorded | A1CBU (4S)-4-(iminomethyl)-3-(isoquinolin-4-yl)-1-[6-(trifluoromethyl)pyridin-3-yl]imidazolidin-2-one × 2 |
X-RAY DIFFRACTION
X-ray crystallization conditions
VAPOR DIFFUSION, HANGING DROP;294 K;0.1M Hepes pH 7.5, 8% Ethylene Glycol, 10% Peg 8000
|
Resolution 3.04 Å R-free 0.278 |
| 9Y8W MERS Mpro with EGT710 Deposited 2025-09-11 | Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics | Assembly 2 Protein homooligomer Homooligomer;Protein × 2 PDB declaration: dimeric |
Chain B
3248–3553(306 aa)
Chain D
3248–3553(306 aa)
|
Not recorded | A1CBU (4S)-4-(iminomethyl)-3-(isoquinolin-4-yl)-1-[6-(trifluoromethyl)pyridin-3-yl]imidazolidin-2-one × 2 |
X-RAY DIFFRACTION
X-ray crystallization conditions
VAPOR DIFFUSION, HANGING DROP;294 K;0.1M Hepes pH 7.5, 8% Ethylene Glycol, 10% Peg 8000
|
Resolution 3.04 Å R-free 0.278 |
| 9YCK Cryo-EM structure of MERS-CoV nsp10-nsp14 (E191A) in complex with T20P15 RNA, monomeric form Deposited 2025-09-19 | Different mutation/modification Different structure-quality metrics | Assembly 1 Protein–RNA Homooligomer;Protein × 2 PDB declaration: trimeric |
Chain A
4238–4377(140 aa)
Chain B
5909–6432(524 aa)
|
Mutation:E191A | ZN ZINC ION × 5 MG MAGNESIUM ION × 1 |
ELECTRON MICROSCOPY
cryo-EM buffer
pH 7.5
cryo-EM vitrification conditions
Cryogen ETHANE
|
Resolution 2.80 Å |
| 9YCL Cryo-EM structure of MERS-CoV nsp10-nsp14 (E191A) in complex with T20P15 RNA, dimeric form Deposited 2025-09-19 | Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different structure-quality metrics | Assembly 1 Protein–RNA Homooligomer;Protein × 4 PDB declaration: hexameric |
Chain A
4238–4377(140 aa)
Chain B
5909–6432(524 aa)
Chain D
4238–4377(140 aa)
Chain E
5909–6432(524 aa)
|
Mutation:E191A Mutation:E191A | ZN ZINC ION × 10 MG MAGNESIUM ION × 2 |
ELECTRON MICROSCOPY
cryo-EM buffer
pH 7.5
cryo-EM vitrification conditions
Cryogen ETHANE
|
Resolution 2.50 Å |
| 9YCM Cryo-EM structure of MERS-CoV nsp10-nsp14 (E191A) in complex with T20P14-U RNA Deposited 2025-09-19 | Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different structure-quality metrics | Assembly 1 Protein–RNA Homooligomer;Protein × 4 PDB declaration: hexameric |
Chain A
4238–4377(140 aa)
Chain B
5909–6432(524 aa)
Chain D
4238–4377(140 aa)
Chain E
5909–6432(524 aa)
|
Mutation:E191A Mutation:E191A | ZN ZINC ION × 10 MG MAGNESIUM ION × 2 |
ELECTRON MICROSCOPY
cryo-EM buffer
pH 7.5
cryo-EM vitrification conditions
Cryogen ETHANE
|
Resolution 2.94 Å |
| 9YCO Cryo-EM structure of MERS-CoV nsp10-nsp14 (E191A) in complex with T20P14-G RNA Deposited 2025-09-19 | Parsed fields agree | Assembly 1 Protein–RNA Homooligomer;Protein × 2 PDB declaration: trimeric |
Chain A
4238–4377(140 aa)
Chain B
5909–6432(524 aa)
|
Not recorded | ZN ZINC ION × 5 MG MAGNESIUM ION × 1 |
ELECTRON MICROSCOPY
cryo-EM buffer
pH 7.5
cryo-EM vitrification conditions
Cryogen ETHANE
|
Resolution 2.88 Å |
11 other PDB entries and 16 assemblies. Open the comparison page and filter oligomeric states
View Construct and Data Evidence
| UniProt name | R1AB_MERS1 |
| Isoform | — |
| PDB entities | 1, 2 |
| Chains and sequence ranges | Author chain A; PDBConstruct 1–140; UniProt 4238–4377 Author chain B; PDBConstruct 1–524; UniProt 5909–6432 |