4FI3

Structure of vitamin B12 transporter BtuCD-F in a nucleotide-bound state

Entity

Entity ID	Chain ID	Description	Type	Chain length	Formula weight	Number of molecules	DB Name (Accession)	Biological source	Descriptive keywords
1	A, B (A, B)	Vitamin B12 import system permease protein BtuC	polymer	349	37650.6	2	UniProt (P06609) Pfam (PF01032)	Escherichia coli
2	C, D (C, D)	Vitamin B12 import ATP-binding protein BtuD	polymer	249	27086.2	2	UniProt (P06611) Pfam (PF00005)	Escherichia coli	Vitamin B12-transporting ATPase
3	E (F)	Vitamin B12-binding protein	polymer	255	28238.1	1	UniProt (P37028) Pfam (PF01497)	Escherichia coli
4	F, H (C, D)	PHOSPHOAMINOPHOSPHONIC ACID-ADENYLATE ESTER	non-polymer		506.2	2	Chemie (ANP)
5	G, I (C, D)	MAGNESIUM ION	non-polymer		24.3	2	Chemie (MG)

Sequence modifications

A, B: 1 - 326 (UniProt: P06609)

PDB	External Database	Details
Met -22	-	expression tag
Gly -21	-	expression tag
His -20	-	expression tag
His -19	-	expression tag
His -18	-	expression tag
His -17	-	expression tag
His -16	-	expression tag
His -15	-	expression tag
His -14	-	expression tag
His -13	-	expression tag
His -12	-	expression tag
His -11	-	expression tag
Ser -10	-	expression tag
Ser -9	-	expression tag
Gly -8	-	expression tag
Glu -7	-	expression tag
Asn -6	-	expression tag
Leu -5	-	expression tag
Tyr -4	-	expression tag
Phe -3	-	expression tag
Gln -2	-	expression tag
Gly -1	-	expression tag
His 0	-	expression tag
Ser 18	Cys 18	engineered mutation
Ser 32	Cys 32	engineered mutation
Ser 120	Cys 120	engineered mutation
Ser 156	Cys 156	engineered mutation
Ser 205	Cys 205	engineered mutation
Ser 206	Cys 206	engineered mutation
Ser 267	Cys 267	engineered mutation

C, D: 1 - 249 (UniProt: P06611)

PDB	External Database	Details
Gln 159	Glu 159	engineered mutation
Cys 162	Asn 162	engineered mutation
Ser 180	Cys 180	engineered mutation

F: 22 - 266 (UniProt: P37028)

PDB	External Database	Details
Met 21	-	expression tag
Ser 267	-	expression tag
Gly 268	-	expression tag
Ser 269	-	expression tag
His 270	-	expression tag
His 271	-	expression tag
His 272	-	expression tag
His 273	-	expression tag
His 274	-	expression tag
His 275	-	expression tag

Contents of the asymmetric unit

Polymers	Number of chains	5
	Total formula weight	157711.7
Non-Polymers*	Number of molecules	4
	Total formula weight	1061.0
All*	Total formula weight	158772.7

*Water molecules are not included.