1LTB: Heat-labile enterotoxin, subunit B
2.6 Å crystal structure of partially-activated E. Coli heat-labile enterotoxin (LT). Determined by X-ray diffraction at 2.6 Å resolution. Released 31 Jan 1994.
- Method
- X-ray diffraction
- Resolution
- 2.6 Å
- Organism
- Escherichia coli
- Chains
- 7
- Atoms
- 6,175
- Mol. weight
- 85.82 kDa
- Released
- 31 Jan 1994
Explore 1LTB in 3D
Show helices and sheets
RCSB PDB
PDBe
Secondary structure: helices and β-sheets
1LTB contains 35 α-helices and 44 β-strands across 7 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: 14 helices, 12 β-strands
| Element | Residues | Length | Sheet |
|---|
| β-strand | 5-9 | 5 | 3 |
| α-helix | 13-18 | 6 | |
| β-strand | 21-22 | 2 | 4 |
| α-helix | 23-24 | 2 | |
| α-helix | 41-46 | 6 | |
| β-strand | 49 | 1 | 5 |
| β-strand | 52 | 1 | 5 |
| β-strand | 59-63 | 5 | 3 |
| α-helix | 66-76 | 11 | |
| β-strand | 82-88 | 7 | 3 |
| β-strand | 94-96 | 3 | 3 |
| α-helix | 97-101 | 5 | |
| α-helix | 102-104 | 3 | |
| α-helix | 108-110 | 3 | |
| β-strand | 112-116 | 5 | 3 |
| β-strand | 119-120 | 2 | 4 |
| α-helix | 121-123 | 3 | |
| β-strand | 124-131 | 8 | 3 |
| β-strand | 134-141 | 8 | 3 |
| α-helix | 147-150 | 4 | |
| α-helix | 155 | 1 | |
| β-strand | 156 | 1 | 3 |
| α-helix | 157 | 1 | |
| α-helix | 158-162 | 5 | |
| α-helix | 172-175 | 4 | |
| α-helix | 179-182 | 4 | |
Chain C: 3 helices, 0 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 197-222 | 26 | |
| α-helix | 223-226 | 4 | |
| α-helix | 232-235 | 4 | |
Chain D: 4 helices, 6 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 5-9 | 5 | |
| β-strand | 15-22 | 8 | 1 |
| β-strand | 26-32 | 7 | 1 |
| β-strand | 35-41 | 7 | 1 |
| β-strand | 47-50 | 4 | 1 |
| α-helix | 51-53 | 3 | |
| α-helix | 61-78 | 18 | |
| β-strand | 82-88 | 7 | 1 |
| α-helix | 94 | 1 | |
| β-strand | 95-102 | 8 | 1 |
Chain E: 4 helices, 6 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 5-10 | 6 | |
| β-strand | 15-22 | 8 | 1 |
| β-strand | 26-30 | 5 | 1 |
| β-strand | 38-41 | 4 | 1 |
| β-strand | 47-50 | 4 | 1 |
| α-helix | 51-53 | 3 | |
| α-helix | 59-77 | 19 | |
| α-helix | 80-81 | 2 | |
| β-strand | 82-88 | 7 | 1 |
| β-strand | 94-102 | 9 | 1 |
Chain F: 3 helices, 6 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 5-9 | 5 | |
| β-strand | 15-22 | 8 | 1 |
| β-strand | 26-30 | 5 | 1 |
| β-strand | 38-41 | 4 | 1 |
| β-strand | 47-50 | 4 | 1 |
| α-helix | 59-78 | 20 | |
| α-helix | 80-81 | 2 | |
| β-strand | 82-88 | 7 | 1 |
| β-strand | 94-102 | 9 | 1 |
Chain G: 3 helices, 6 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 5-9 | 5 | |
| β-strand | 15-23 | 9 | 1 |
| β-strand | 26-30 | 5 | 1 |
| β-strand | 38-41 | 4 | 1 |
| β-strand | 47-50 | 4 | 1 |
| α-helix | 59-77 | 19 | |
| α-helix | 80 | 1 | |
| β-strand | 81-88 | 8 | 1 |
| β-strand | 94-102 | 9 | 1 |
Chain H: 4 helices, 8 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 5-9 | 5 | |
| β-strand | 15-23 | 9 | 1 |
| β-strand | 26-30 | 5 | 1 |
| β-strand | 32 | 1 | 2 |
| β-strand | 35 | 1 | 2 |
| β-strand | 38-41 | 4 | 1 |
| β-strand | 47-50 | 4 | 1 |
| α-helix | 51-53 | 3 | |
| α-helix | 59-78 | 20 | |
| α-helix | 80 | 1 | |
| β-strand | 81-88 | 8 | 1 |
| β-strand | 94-102 | 9 | 1 |
Molecules and chains
| Molecule | Chains | Type | Length | Organism | UniProt |
|---|
| Heat-labile enterotoxin, subunit B | D, E, F, G, H | protein | 103 | Escherichia coli | P32890 (AlphaFold model) |
| Heat-labile enterotoxin, subunit A | A | protein | 185 | Escherichia coli | P06717 (AlphaFold model) |
| Heat-labile enterotoxin, subunit A | C | protein | 45 | Escherichia coli | P06717 (AlphaFold model) |
Sequence of entity 1 (D, E, F, G, H), FASTA
>1LTB_1 HEAT-LABILE ENTEROTOXIN, SUBUNIT B (chains D, E, F, G, H)
APQTITELCSEYRNTQIYTINDKILSYTESMAGKREMVIITFKSGETFQVEVPGSQHIDS
QKKAIERMKDTLRITYLTETKIDKLCVWNNKTPNSIAAISMKN
Sequence of entity 2 (A), FASTA
>1LTB_2 HEAT-LABILE ENTEROTOXIN, SUBUNIT A (chains A)
RLYRADSRPPDEIKRSGGLMPRGHNEYFDRGTQMNINLYDHARGTQTGFVRYDDGYVSTS
LSLRSAHLAGQSILSGYSTYYIYVIATAPNMFNVNDVLGVYSPHPYEQEVSALGGIPYSQ
IYGWYRVNFGVIDERLHRNREYRDRYYRNLNIAPAEDGYRLAGFPPDHQAWREEPWIHHA
PQGCG
Sequence of entity 3 (C), FASTA
>1LTB_3 HEAT-LABILE ENTEROTOXIN, SUBUNIT A (chains C)
RTITGDTCNEETQNLSTIYLREYQSKVKRQIFSDYQSEVDIYNRI
Primary citation
Structure of partially-activated E. coli heat-labile enterotoxin (LT) at 2.6 A resolution. Merritt, E.A., Pronk, S.E., Sixma, T.K. et al. FEBS Lett (1994) 337:88-92. DOI 10.1016/0014-5793(94)80635-7 · PubMed
Other PDB entries of the same protein (UniProt P32890 (AlphaFold model), which also has an AlphaFold model), best resolution first:
- 1DJR 1.3 Å, Heat-labile enterotoxin B-pentamer complexed with M-carboxyphenyl-alpha-D-galactose
- 6IAL 1.45 Å, Porcine E.coli heat-labile enterotoxin B-pentamer in complex with Lacto-N-neohexaose
- 1EFI 1.6 Å, Heat-labile enterotoxin B-pentamer complexed with para-aminophenyl-alpha-D-galactopyranos…
- 5LZI 1.6 Å, Porcine heat-labile enterotoxin R13H in complex with inhibitor MM146
- 1LT5 1.7 Å, Heat-labile enterotoxin B-pentamer complexed with thiodigalactoside
- 1EEF 1.8 Å, Heat-labile enterotoxin B-pentamer complexed with bound ligand pepg
- 1FD7 1.8 Å, Heat-labile enterotoxin B-pentamer with bound ligand BMSC001
- 2XRS 1.81 Å, Crystal structures exploring the origins of the broader specificity of escherichia coli…
- 1LTS 1.95 Å, Refined structure of E. Coli heat labile enterotoxin, a close relative of cholera toxin
- 1PZI 1.99 Å, Heat-Labile Enterotoxin B-Pentamer Complexed With Nitrophenyl Galactoside 2a
- 1LT3 2.0 Å, Heat-labile enterotoxin double mutant N40C/G166C
- 1LT4 2.0 Å, Heat-labile enterotoxin mutant S63K
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