4R9U

Structure of vitamin B12 transporter BtuCD in a nucleotide-bound outward facing 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	333	35484.3	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, G, H (A, B)	LAURYL DIMETHYLAMINE-N-OXIDE	non-polymer		229.4	4	Chemie (LDA)
4	I, K (C, D)	PHOSPHOAMINOPHOSPHONIC ACID-ADENYLATE ESTER	non-polymer		506.2	2	Chemie (ANP)
5	J, L (C, D)	MAGNESIUM ION	non-polymer		24.3	2	Chemie (MG)

Sequence modifications

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

PDB	External Database	Details
Gly -6	-	expression tag
Pro -5	-	expression tag
Ser -4	-	expression tag
Gly -3	-	expression tag
Thr -2	-	expression tag
Ser -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

Contents of the asymmetric unit

Polymers	Number of chains	4
	Total formula weight	125140.9
Non-Polymers*	Number of molecules	8
	Total formula weight	1978.6
All*	Total formula weight	127119.5

*Water molecules are not included.