4FI3: Vitamin B12 import system permease protein BtuC

Structure of vitamin B12 transporter BtuCD-F in a nucleotide-bound state. Determined by X-ray diffraction at 3.47 Å resolution. Released 19 Sept 2012.

Method: X-ray diffraction
Resolution: 3.47 Å
Organism: Escherichia coli
Chains: 5
Atoms: 10,635
Mol. weight: 158.77 kDa
Ligands: MG, ANP
Released: 19 Sept 2012

Explore 4FI3 in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

4FI3 contains 72 α-helices and 42 β-strands across 5 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: 17 helices, 0 β-strands

Element	Residues	Length
α-helix	3-31	29
α-helix	42-44	3
α-helix	49-51	3
α-helix	56-81	26
α-helix	88-90	3
α-helix	93-106	14
α-helix	114-136	23
α-helix	142-163	22
α-helix	169-179	11
α-helix	188-190	3
α-helix	191-206	16
α-helix	209-214	6
α-helix	218-223	6
α-helix	228-249	22
α-helix	256-265	10
α-helix	272-295	24
α-helix	305-323	19

Chain B: 17 helices, 0 β-strands

Element	Residues	Length
α-helix	3-31	29
α-helix	42-44	3
α-helix	49-51	3
α-helix	56-81	26
α-helix	88-91	4
α-helix	93-106	14
α-helix	114-136	23
α-helix	142-166	25
α-helix	169-179	11
α-helix	188-190	3
α-helix	191-206	16
α-helix	209-214	6
α-helix	218-223	6
α-helix	228-249	22
α-helix	256-265	10
α-helix	272-295	24
α-helix	305-323	19

Chain C: 12 helices, 14 β-strands

Element	Residues	Length	Sheet
β-strand	5-12	8	1
β-strand	16-23	8	1
β-strand	28-32	5	2
α-helix	39-47	9
β-strand	55-58	4	1
β-strand	61-62	2	1
α-helix	63-65	3
α-helix	68-74	7
β-strand	75-78	4	2
α-helix	83-85	3
β-strand	89	1	3
α-helix	90-97	8
α-helix	104-113	10
β-strand	123	1	3
α-helix	124-126	3
α-helix	129-144	16
β-strand	154-157	4	2
α-helix	166-181	16
β-strand	185-189	5	2
α-helix	193-199	7
β-strand	202-207	6	2
β-strand	210-216	7	2
α-helix	217-220	4
α-helix	223-230	8
β-strand	233-239	7	4
β-strand	242-248	7	4

Chain D: 12 helices, 14 β-strands

Element	Residues	Length	Sheet
β-strand	5-12	8	5
β-strand	16-23	8	5
β-strand	28-32	5	6
α-helix	39-46	8
β-strand	55-58	4	5
β-strand	61-62	2	5
α-helix	63-65	3
α-helix	68-74	7
β-strand	75-78	4	6
α-helix	83-85	3
β-strand	89	1	7
α-helix	90-97	8
α-helix	104-113	10
β-strand	123	1	7
α-helix	124-126	3
α-helix	129-144	16
β-strand	154-157	4	6
α-helix	166-181	16
β-strand	185-189	5	6
α-helix	193-199	7
β-strand	202-207	6	6
β-strand	210-216	7	6
α-helix	217-220	4
α-helix	223-230	8
β-strand	233-239	7	8
β-strand	242-248	7	8

Chain F: 14 helices, 14 β-strands

Element	Residues	Length	Sheet
β-strand	26-28	3	9
α-helix	31-40	10
β-strand	46	1	9
β-strand	47	1	10
α-helix	55-59	5
α-helix	61	1
β-strand	62	1	10
β-strand	64	1	11
β-strand	69	1	11
α-helix	71-76	6
β-strand	81-84	4	9
α-helix	91-99	9
β-strand	103-106	4	9
α-helix	113-122	10
α-helix	123-125	3
α-helix	129-151	23
α-helix	154-155	2
β-strand	156-160	5	12
β-strand	168	1	13
α-helix	175-182	8
β-strand	185-187	3	12
β-strand	198	1	13
α-helix	201-205	5
β-strand	211-215	5	12
α-helix	222-227	6
β-strand	236-239	4	12
α-helix	241-245	5
α-helix	251-263	13

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Vitamin B12 import system permease protein BtuC	A, B	protein	349	Escherichia coli	P06609 (AlphaFold model)
Vitamin B12 import ATP-binding protein BtuD	C, D	protein	249	Escherichia coli	P06611 (AlphaFold model)
Vitamin B12-binding protein	F	protein	255	Escherichia coli	P37028 (AlphaFold model)

Sequence of entity 1 (A, B), FASTA

>4FI3_1 Vitamin B12 import system permease protein BtuC (chains A, B)
MGHHHHHHHHHHSSGENLYFQGHMLTLARQQQRQNIRWLLSLSVLMLLALLLSLSAGEQW
ISPGDWFTPRGELFVWQIRLPRTLAVLLVGAALAISGAVMQALFENPLAEPGLLGVSNGA
GVGLIAAVLLGQGQLPNWALGLSAIAGALIITLILLRFARRHLSTSRLLLAGVALGIISS
ALMTWAIYFSTSVDLRQLMYWMMGGFGGVDWRQSWLMLALIPVLLWISSQSRPMNMLALG
EISARQLGLPLWFWRNVLVAATGWMVGVSVALAGAIGFIGLVIPHILRLSGLTDHRVLLP
GCALAGASALLLADIVARLALAAAELPIGVVTATLGAPVFIWLLLKAGR

Sequence of entity 2 (C, D), FASTA

>4FI3_2 Vitamin B12 import ATP-binding protein BtuD (chains C, D)
MSIVMQLQDVAESTRLGPLSGEVRAGEILHLVGPNGAGKSTLLARMAGMTSGKGSIQFAG
QPLEAWSATKLALHRAYLSQQQTPPFATPVWHYLTLHQHDKTRTELLNDVAGALALDDKL
GRSTNQLSGGEWQRVRLAAVVLQITPQANPAGQLLLLDQPMCSLDVAQQSALDKILSALS
QQGLAIVMSSHDLNHTLRHAHRAWLLKGGKMLASGRREEVLTPPNLAQAYGMNFRRLDIE
GHRMLISTI

Sequence of entity 3 (F), FASTA

>4FI3_3 Vitamin B12-binding protein (chains F)
MAAPRVITLSPANTELAFAAGITPVGVSSYSDYPPQAQKIEQVSTWQGMNLERIVALKPD
LVIAWRGGNAERQVDQLASLGIKVMWVDATSIEQIANALRQLAPWSPQPDKAEQAAQSLL
DQYAQLKAQYADKPKKRVFLQFGINPPFTSGKESIQNQVLEVCGGENIFKDSRVPWPQVS
REQVLARSPQAIVITGGPDQIPKIKQYWGEQLKIPVIPLTSDWFERASPRIILAAQQLCN
ALSQVDSGSHHHHHH

Ligands and cofactors

ID	Name	Formula	Copies
MG	Magnesium ion	Mg	2
ANP	Phosphoaminophosphonic acid-adenylate ester	C10 H17 N6 O12 P3	2

Primary citation

Structure of AMP-PNP-bound vitamin B12 transporter BtuCD-F. Korkhov, V.M., Mireku, S.A., Locher, K.P. Nature (2012) 490:367-372. DOI 10.1038/nature11442 · PubMed

Other PDB entries of the same protein (UniProt P06609 (AlphaFold model), which also has an AlphaFold model), best resolution first:

2QI9 2.6 Å, ABC-transporter BtuCD in complex with its periplasmic binding protein BtuF
4R9U 2.79 Å, Structure of vitamin B12 transporter BtuCD in a nucleotide-bound outward facing state
1L7V 3.2 Å, Bacterial ABC Transporter Involved in B12 Uptake
4DBL 3.49 Å, Crystal structure of E159Q mutant of BtuCDF

Browse structure collections

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