8SKV

Structure of human SIgA1 in complex with Streptococcus pyogenes protein M4 (Arp4)

Entity

Entity ID	Chain ID	Description	Type	Chain length	Formula weight	Number of molecules	DB Name (Accession)	Biological source	Descriptive keywords
1	A, B, C, D (A, B, C, D)	Immunoglobulin heavy constant alpha 1	polymer	353	37687.5	4	UniProt (P01876) Pfam (PF07654) Pfam (PF00047)	Homo sapiens (human)	Ig alpha-1 chain C region,Ig alpha-1 chain C region BUR,Ig alpha-1 chain C region TRO
2	E (E)	Secretory component	polymer	553	61095.6	1	UniProt (P01833) Pfam (PF07686)	Homo sapiens (human)	Polymeric immunoglobulin receptor
3	F (J)	Immunoglobulin J chain	polymer	137	15611.5	1	UniProt (P01591) Pfam (PF15097)	Homo sapiens (human)	Joining chain of multimeric IgA and IgM
4	G, H (a, b)	IgA receptor	polymer	321	37352.7	2	UniProt (P13050) Pfam (PF02370)	Streptococcus pyogenes serotype M4
5	I, J, K, L (G, H, I, O)	2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose	branched		424.4	4	In PDB GlyTouCan (G42666HT)
6	M, N, O, P, Q... (A, B, E)	2-acetamido-2-deoxy-beta-D-glucopyranose	non-polymer		221.2	7	Chemie (NAG)

Sequence modifications

E: 1 - 547 (UniProt: P01833)

PDB	External Database	Details
His 548	-	expression tag
His 549	-	expression tag
His 550	-	expression tag
His 551	-	expression tag
His 552	-	expression tag
His 553	-	expression tag

a, b: 1 - 315 (UniProt: P13050)

PDB	External Database	Details
His 316	-	expression tag
His 317	-	expression tag
His 318	-	expression tag
His 319	-	expression tag
His 320	-	expression tag
His 321	-	expression tag

Contents of the asymmetric unit

Polymers	Number of chains	8
	Total formula weight	302162.3
Branched	Number of molecules	4
	Total formula weight	1697.6
Non-Polymers*	Number of molecules	7
	Total formula weight	1548.5
All*	Total formula weight	305408.4

*Water molecules are not included.