4L41

Human Lactose synthase: A 2:1 complex between human alpha-lactalbumin and human beta1,4-galactosyltransferase

Entity

Entity ID	Chain ID	Description	Type	Chain length	Formula weight	Number of molecules	DB Name (Accession)	Biological source	Descriptive keywords
1	A, C (A, B)	Alpha-lactalbumin	polymer	124	14164.2	2	UniProt (P00709) Pfam (PF00062)	Homo sapiens (human)	Lactose synthase B protein, Lysozyme-like protein 7
2	B (C)	Beta-1,4-galactosyltransferase 1	polymer	287	32766.3	1	UniProt (P15291) Pfam (PF13733) Pfam (PF02709)	Homo sapiens (human)	Beta-1,4-GalTase 1, Beta4Gal-T1, b4Gal-T1
3	D, F (A, B)	CALCIUM ION	non-polymer		40.1	2	Chemie (CA)
4	E (C)	SULFATE ION	non-polymer		96.1	1	Chemie (SO4)
5	G, H, I (A, C, B)	water	water		18.0	31	Chemie (HOH)

Sequence modifications

C: 126 - 398 (UniProt: P15291)

PDB	External Database	Details
Ala 112	-	expression tag
Ser 113	-	expression tag
Met 114	-	expression tag
Thr 115	-	expression tag
Gly 116	-	expression tag
Gly 117	-	expression tag
Gln 118	-	expression tag
Gln 119	-	expression tag
Met 120	-	expression tag
Gly 121	-	expression tag
Arg 122	-	expression tag
Gly 123	-	expression tag
Ser 124	-	expression tag
Ala 125	-	expression tag
Thr 337	Arg 337	engineered mutation
Thr 338	Cys 338	engineered mutation

Contents of the asymmetric unit

Polymers	Number of chains	3
	Total formula weight	61094.7
Non-Polymers*	Number of molecules	3
	Total formula weight	176.2
All*	Total formula weight	61270.9

*Water molecules are not included.