7K0C

Structure of Secretory IgM Core

Entity

Entity ID	Chain ID	Description	Type	Chain length	Formula weight	Number of molecules	DB Name (Accession)	Biological source	Descriptive keywords
1	A (C)	Polymeric immunoglobulin receptor	polymer	591	65154.1	1	UniProt (P01833) Pfam (PF07686)	Homo sapiens (Human)	Poly-Ig receptor,Hepatocellular carcinoma-associated protein TB6
2	B, C, D, E, F... (A, B, K, L, I...)	Immunoglobulin heavy constant mu	polymer	369	40677.6	10	UniProt (P01871) Pfam (PF07654)	Homo sapiens (Human)	Ig mu chain C region,Ig mu chain C region BOT,Ig mu chain C region GAL,Ig mu chain C region OU
3	J (D)	Immunoglobulin J chain	polymer	137	15611.5	1	UniProt (P01591) Pfam (PF15097)	Homo sapiens (Human)	Joining chain of multimeric IgA and IgM
4	M (M)	2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose	branched		424.4	1	In PDB GlyTouCan (G42666HT)

Sequence modifications

C: 1 - 585 (UniProt: P01833)

PDB	External Database	Details
His 586	-	expression tag
His 587	-	expression tag
His 588	-	expression tag
His 589	-	expression tag
His 590	-	expression tag
His 591	-	expression tag

A, B, K, L, I, J, E, H, G, F: 226 - 576 (UniProt: P01871)

PDB	External Database	Details
Asp 208	-	expression tag
Tyr 209	-	expression tag
Lys 210	-	expression tag
Asp 211	-	expression tag
Asp 212	-	expression tag
Asp 213	-	expression tag
Asp 214	-	expression tag
Lys 215	-	expression tag
Leu 216	-	expression tag
Glu 217	-	expression tag
Val 218	-	expression tag
Leu 219	-	expression tag
Phe 220	-	expression tag
Gln 221	-	expression tag
Gly 222	-	expression tag
Pro 223	-	expression tag
Gly 224	-	expression tag
Ser 225	-	expression tag

Contents of the asymmetric unit

Polymers	Number of chains	12
	Total formula weight	487541.6
Branched	Number of molecules	1
	Total formula weight	424.4
All*	Total formula weight	487966.0

*Water molecules are not included.