2GSK: BtuB:TonB Complex

Structure of the BtuB:TonB Complex. Determined by X-ray diffraction at 2.1 Å resolution. Released 13 Jun 2006.

Method: X-ray diffraction
Resolution: 2.1 Å
Organism: Escherichia coli
Chains: 2
Atoms: 5,658
Mol. weight: 78.07 kDa
Ligands: HEX, OCT, LDA, CNC
Released: 13 Jun 2006

Explore 2GSK in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

2GSK contains 16 α-helices and 45 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: 13 helices, 39 β-strands

Element	Residues	Length	Sheet
β-strand	6-11	6	1
β-strand	26-30	5	2
α-helix	31-37	7
α-helix	42-46	5
β-strand	52-56	5	3
β-strand	64-68	5	3
α-helix	73-75	3
β-strand	76-80	5	2
β-strand	83-84	2	2
α-helix	85-86	2
α-helix	96-98	3
α-helix	101-103	3
β-strand	106-111	6	2
α-helix	115-118	4
β-strand	125-130	6	2
β-strand	137-145	9	4
β-strand	149-161	13	4
β-strand	164-178	15	4
β-strand	181	1	5
β-strand	187	1	6
β-strand	195-209	15	4
β-strand	214-228	15	4
β-strand	233	1	6
β-strand	242-257	16	4
β-strand	261-277	17	4
β-strand	289-305	17	4
β-strand	309-322	14	4
α-helix	326-328	3
β-strand	333-348	16	4
β-strand	351-362	12	4
β-strand	366-380	15	4
β-strand	383-394	12	4
α-helix	395-397	3
α-helix	398-402	5
α-helix	410-412	3
β-strand	413-426	14	4
β-strand	429-441	13	4
β-strand	444-447	4	7
β-strand	452-455	4	7
β-strand	459-472	14	4
β-strand	475-488	14	4
β-strand	493-494	2	4
α-helix	495	1
β-strand	501-511	11	4
β-strand	514-523	10	4
β-strand	526-530	5	8
β-strand	537-541	5	8
α-helix	542-543	2
β-strand	544-554	11	4
β-strand	559-566	8	4
β-strand	579	1	5
β-strand	585-593	9	4

Chain B: 3 helices, 6 β-strands

Element	Residues	Length	Sheet
β-strand	155-157	3	9
α-helix	160-164	5
α-helix	165-169	5
β-strand	174-182	9	1
β-strand	187	1	9
β-strand	188-197	10	1
α-helix	203-210	8
β-strand	214-215	2	9
β-strand	221-231	11	1

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Vitamin B12 transporter btuB	A	protein	590	Escherichia coli	P06129 (AlphaFold model)
protein TONB	B	protein	81	Escherichia coli	P02929 (AlphaFold model)

Sequence of entity 1 (A), FASTA

>2GSK_1 Vitamin B12 transporter btuB (chains A)
PDTLVVTANRFEQPRSTVLAPTTVVTRQDIDRWQSTSVNDVLRRLPGVDITQNGGSGQLS
SIFIRGTNASHVLVLIDGVRLNLAGVSGSADLSQFPIALVQRVEYIRGPRSAVYGSDAIG
GVVNIITTRDEPGTEISAGWGSNSYQNYDVSTQQQLGDKTRVTLLGDYAHTHGYDVVAYG
NTGTQAQTDNDGFLSKTLYGALEHNFTDAWSGFVRGYGYDNRTNYDAYYSPGSPLLDTRK
LYSQSWDAGLRYNGELIKSQLITSYSHSKDYNYDPHYGRYDSSATLDEMKQYTVQWANNV
IVGHGSIGAGVDWQKQTTTPGTGYVEDGYDQRNTGIYLTGLQQVGDFTFEGAARSDDNSQ
FGRHGTWQTSAGWEFIEGYRFIASYGTSYKAPNLGQLYGFYGNPNLDPEKSKQWEGAFEG
LTAGVNWRISGYRNDVSDLIDYDDHTLKYYNEGKARIKGVEATANFDTGPLTHTVSYDYV
DARNAITDTPLLRRAKQQVKYQLDWQLYDFDWGITYQYLGTRYDKDYSSYPYQTVKMGGV
SLWDLAVAYPVTSHLTVRGKIANLFDKDYETVYGYQTAGREYTLSGSYTF

Sequence of entity 2 (B), FASTA

>2GSK_2 protein TONB (chains B)
PRALSRNQPQYPARAQALRIEGQVKVKFDVTPDGRVDNVQILSAKPANMFEREVKNAMRR
WRYEPGKPGSGIVVNILFKIN

Ligands and cofactors

ID	Name	Formula	Copies
HEX	Hexane	C6 H14	2
OCT	N-octane	C8 H18	3
LDA	Lauryl dimethylamine-N-oxide	C14 H31 N O	4
CNC	Cyanocobalamin	C63 H89 Co N14 O14 P	1
CA	Calcium ion	Ca	2

Primary citation

Outer membrane active transport: structure of the BtuB:TonB complex. Shultis, D.D., Purdy, M.D., Banchs, C.N. et al. Science (2006) 312:1396-1399. DOI 10.1126/science.1127694 · PubMed

Other PDB entries of the same protein (UniProt P06129 (AlphaFold model), which also has an AlphaFold model), best resolution first:

2GUF 1.95 Å, In meso crystal structure of the cobalamin transporter, BtuB
1NQE 2.0 Å, Outer membrane cobalamin transporter (BTUB) from E. Coli
3RGN 2.3 Å, Crystal structure of spin-labeled BtuB W371R1
3M8B 2.44 Å, Crystal structure of spin-labeled BtuB V10R1 in the apo state
3M8D 2.44 Å, Crystal structure of spin-labeled BtuB V10R1 with bound calcium and cyanocobalamin
3RGM 2.6 Å, Crystal structure of spin-labeled BtuB T156R1
1NQF 2.7 Å, Outer membrane cobalamin transporter (BTUB) from E. Coli, methionine substiution…
1UJW 2.75 Å, Structure of the complex between BtuB and Colicin E3 Receptor binding domain
1NQH 3.1 Å, Outer membrane cobalamin transporter (BTUB) from E. Coli, with bound calcium and…
1NQG 3.31 Å, Outer membrane cobalamin transporter (BTUB) from E. Coli, with bound calcium
2YSU 3.5 Å, Structure of the complex between BtuB and Colicin E2 receptor binding domain
7NSU 4.7 Å, ColicinE9 intact translocation complex

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