8Q6I: Cholera holotoxin variant

Name: PDB 8Q6I: Cholera holotoxin variant (chimera with E. coli heat-labile enterotoxin, 1 C-terminal substitution)
Published: 2025-02-12
License: https://creativecommons.org/publicdomain/zero/1.0/
Keywords: toxin

Cholera holotoxin variant (chimera with E. coli heat-labile enterotoxin, 1 C-terminal substitution). Determined by X-ray diffraction at 1.6 Å resolution. Released 12 Feb 2025.

Method: X-ray diffraction
Resolution: 1.6 Å
Organism: Vibrio cholerae O1
Chains: 6
Atoms: 6,874
Mol. weight: 86.64 kDa
Released: 12 Feb 2025

Explore 8Q6I in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

8Q6I contains 43 α-helices and 41 β-strands across 6 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: 21 helices, 11 β-strands

Element	Residues	Length	Sheet
β-strand	4-9	6	1
α-helix	13-19	7
β-strand	21-22	2	2
α-helix	23-24	2
α-helix	36-38	3
α-helix	41-45	5
α-helix	47-49	3
β-strand	59-62	4	3
β-strand	63	1	1
α-helix	66-77	12
β-strand	82-89	8	1
β-strand	94-96	3	3
α-helix	97-101	5
α-helix	102-104	3
α-helix	108-110	3
β-strand	113-116	4	3
β-strand	119-120	2	2
α-helix	121-123	3
β-strand	124-131	8	1
β-strand	134-135	2	1
α-helix	136	1
β-strand	140-141	2	1
α-helix	142	1
α-helix	147-150	4
α-helix	155-157	3
α-helix	158-160	3
α-helix	162-164	3
α-helix	172-175	4
α-helix	179-181	3
α-helix	183-184	2
α-helix	198-223	26
α-helix	224-226	3

Chains D and F: 4 helices, 6 β-strands

Element	Residues	Length	Sheet
α-helix	5-9	5
β-strand	15-22	8	4
β-strand	26-30	5	4
β-strand	37-41	5	4
β-strand	47-50	4	4
α-helix	51-53	3
α-helix	59-78	20
α-helix	80-81	2
β-strand	82-88	7	4
β-strand	94-102	9	4

Chains E and H: 5 helices, 6 β-strands

Element	Residues	Length	Sheet
α-helix	5-9	5
β-strand	15-22	8	4
β-strand	26-30	5	4
β-strand	37-41	5	4
β-strand	47-50	4	4
α-helix	51-53	3
α-helix	59-61	3
α-helix	62-78	17
α-helix	80-81	2
β-strand	82-88	7	4
β-strand	94-102	9	4

Chain G: 4 helices, 6 β-strands

Element	Residues	Length	Sheet
α-helix	5-9	5
β-strand	15-22	8	4
β-strand	26-30	5	4
β-strand	37-41	5	4
β-strand	47-50	4	4
α-helix	51-53	3
α-helix	61-78	18
α-helix	80-81	2
β-strand	82-88	7	4
β-strand	94-102	9	4

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Cholera enterotoxin subunit A	A	protein	240	Vibrio cholerae O1	P01555 (AlphaFold model)
Cholera enterotoxin subunit B	D, E, F, G, H	protein	103	Vibrio cholerae O1	P01556 (AlphaFold model)

Sequence of entity 1 (A), FASTA

>8Q6I_1 Cholera enterotoxin subunit A (chains A)
NDDKLYRADSRPPDEIKQSGGLMPRGQSEYFDRGTQMNINLYDHARGTQTGFVRHDDGYV
STSISLRSAHLVGQTILSGHSTYYIYVIATAPNMFNVNDVLGAYSPHPDEQEVSALGGIP
YSQIYGWYRVHFGVLDEQLHRNRGYRDRYYSNLDIAPAADGYGLAGFPPEHRAWREEPWI
HHAPPGCGNAPRSSMSNTCDEKTQSLGVKFLDEYQSKVKRQIFSGYQSEIDTHNRIKDEL

Sequence of entity 2 (D, E, F, G, H), FASTA

>8Q6I_2 Cholera enterotoxin subunit B (chains D, E, F, G, H)
TPQNITDLCAEYHNTQIHTLNDKIFSYTESLAGKREMAIITFKNGATFQVEVPGSQHIDS
QKKAIERMKDTLRIAYLTEAKVEKLCVWNNKTPHAIAAISMAN

Primary citation

Cholera toxin variants. Kersten, F., Serrano, A., Mojica, N. et al. To be published.

Other PDB entries of the same protein (UniProt P01555 (AlphaFold model), which also has an AlphaFold model), best resolution first:

8OXS 1.6 Å, Cholera holotoxin variant (chimera with E. coli heat-labile enterotoxin, 4 C-terminal…
1S5D 1.75 Å, Cholera holotoxin with an A-subunit Y30S mutation, Crystal form 2
2A5D 1.8 Å, Structural basis for the activation of cholera toxin by human ARF6-GTP
1S5E 1.9 Å, Cholera holotoxin, Crystal form 1
2A5F 2.02 Å, Cholera toxin A1 subunit bound to its substrate, NAD+, and its human protein activator,…
1S5B 2.13 Å, Cholera holotoxin with an A-subunit Y30S mutation Form 3
8QRE 2.3 Å, Cholera holotoxin (wildtype)
1XTC 2.4 Å, Cholera toxin
1S5C 2.5 Å, Cholera holotoxin with an A-subunit Y30S mutation, Crystal form 1
1S5F 2.6 Å, Cholera holotoxin, Crystal form 2
2A5G 2.66 Å, Cholera toxin A1 subunit bound to ARF6(Q67L)

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