6LXW

Cryo-EM structure of human secretory immunoglobulin A in complex with the N-terminal domain of SpsA

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)	Interleukin-2,Immunoglobulin heavy constant alpha 1	polymer	291	31445.7	4	UniProt (P60568) UniProt (P01876) Pfam (PF00047) Pfam (PF07654)	Homo sapiens (Human)	IL-2,T-cell growth factor,TCGF,Ig alpha-1 chain C region,Ig alpha-1 chain C region BUR,Ig alpha-1 chain C region TRO
2	E (J)	Immunoglobulin J chain	polymer	167	19225.8	1	UniProt (P01591) Pfam (PF15097)	Homo sapiens (Human)	Joining chain of multimeric IgA and IgM
3	F (P)	Polymeric immunoglobulin receptor	polymer	573	63306.3	1	UniProt (P01833) Pfam (PF07686)	Homo sapiens (Human)	Poly-Ig receptor,Hepatocellular carcinoma-associated protein TB6
4	G (S)	SigA binding protein	polymer	317	36311.1	1	UniProt (O33753)	Streptococcus pneumoniae

Sequence modifications

A, B, C, D: 182 - 202 (UniProt: P60568)

PDB	External Database	Details
Arg 203	-	linker
Ile 204	-	linker
His 205	-	linker
Met 206	-	linker
Ser 207	-	linker
Ala 208	-	linker
Trp 209	-	linker
Ser 210	-	linker
His 211	-	linker
Pro 212	-	linker
Gln 213	-	linker
Phe 214	-	linker
Glu 215	-	linker
Lys 216	-	linker
Gly 217	-	linker
Gly 218	-	linker
Gly 219	-	linker
Ser 220	-	linker
Gly 221	-	linker
Gly 222	-	linker
Gly 223	-	linker
Ser 224	-	linker
Gly 225	-	linker
Gly 226	-	linker
Ser 227	-	linker
Ala 228	-	linker
Trp 229	-	linker
Ser 230	-	linker
His 231	-	linker
Pro 232	-	linker
Gln 233	-	linker
Phe 234	-	linker
Glu 235	-	linker
Lys 236	-	linker
Ile 237	-	linker
Asp 238	-	linker
Thr 239	-	linker
Thr 240	-	linker

A, B, C, D: 241 - 472 (UniProt: P01876)
J: -22 - 136 (UniProt: P01591)

PDB	External Database	Details
His 137	-	expression tag
His 138	-	expression tag
His 139	-	expression tag
His 140	-	expression tag
His 141	-	expression tag
His 142	-	expression tag
His 143	-	expression tag
His 144	-	expression tag

P: -17 - 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
His 554	-	expression tag
His 555	-	expression tag

S: 38 - 324 (UniProt: O33753)

PDB	External Database	Details
Met 8	-	initiating methionine
Gly 9	-	expression tag
Ser 10	-	expression tag
His 11	-	expression tag
His 12	-	expression tag
His 13	-	expression tag
His 14	-	expression tag
His 15	-	expression tag
His 16	-	expression tag
His 17	-	expression tag
His 18	-	expression tag
Gly 19	-	expression tag
Ser 20	-	expression tag
Asp 21	-	expression tag
Tyr 22	-	expression tag
Asp 23	-	expression tag
Ile 24	-	expression tag
Pro 25	-	expression tag
Thr 26	-	expression tag
Thr 27	-	expression tag
Glu 28	-	expression tag
Asn 29	-	expression tag
Leu 30	-	expression tag
Tyr 31	-	expression tag
Phe 32	-	expression tag
Gln 33	-	expression tag
Gly 34	-	expression tag
Ser 35	-	expression tag
Glu 36	-	expression tag
Phe 37	-	expression tag

Contents of the asymmetric unit

Polymers	Number of chains	7
	Total formula weight	244626.0
All*	Total formula weight	244626.0

*Water molecules are not included.