2QI9

ABC-transporter BtuCD in complex with its periplasmic binding protein BtuF

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	326	35375.5	2	UniProt (P06609) Pfam (PF01032)	Escherichia coli
2	C, D (C, D)	Vitamin B12 import ATP-binding protein btuD	polymer	249	27520.2	2	UniProt (P06611) Pfam (PF00005)	Escherichia coli	Vitamin B12-transporting ATPase
3	E (F)	Vitamin B12-binding protein btuF	polymer	245	27140.6	1	UniProt (P37028) Pfam (PF01497)	Escherichia coli
4	F, M (C, D)	PHOSPHATE ION	non-polymer		95.0	2	Chemie (PO4)
5	G, H, I, N, O... (C, D)	SULFATE ION	non-polymer		96.1	6	Chemie (SO4)
6	J, Q (C, D)	PENTAETHYLENE GLYCOL	non-polymer		238.3	2	Chemie (1PE)
7	K, L, R, S (C, D)	DI(HYDROXYETHYL)ETHER	non-polymer		106.1	4	Chemie (PEG)
8	T, U (C, D)	water	water		18.0	16	Chemie (HOH)

Sequence modifications

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

PDB	External Database	Details
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
Ser 180	Cys 180	engineered mutation

Contents of the asymmetric unit

Polymers	Number of chains	5
	Total formula weight	152931.9
Non-Polymers*	Number of molecules	14
	Total formula weight	1667.4
All*	Total formula weight	154599.3

*Water molecules are not included.