4QNH

Calcium-calmodulin (T79D) complexed with the calmodulin binding domain from a small conductance potassium channel SK2-a

Entity

Entity ID	Chain ID	Description	Type	Chain length	Formula weight	Number of molecules	DB Name (Accession)	Biological source	Descriptive keywords
1	A (B)	Small conductance calcium-activated potassium channel protein 2	polymer	102	12243.4	1	UniProt (P70604) Pfam (PF02888)	Rattus norvegicus (rat)	SK2, SKCa 2, SKCa2, KCa2.2
2	B (R)	Calmodulin	polymer	149	16866.5	1	UniProt (P62161) Pfam (PF13499) UniProt (by SIFTS) (P0DP29)	Rattus norvegicus (rat)	CaM
3	C (B)	SULFATE ION	non-polymer		96.1	1	Chemie (SO4)
4	D, E (R)	CALCIUM ION	non-polymer		40.1	2	Chemie (CA)
5	F, G (B, R)	water	water		18.0	187	Chemie (HOH)

Sequence modifications

B: 396 - 487 (UniProt: P70604)

PDB	External Database	Details
Met 394	-	initiating methionine
Gly 395	-	expression tag
Leu 488	-	expression tag
Glu 489	-	expression tag
His 490	-	expression tag
His 491	-	expression tag
His 492	-	expression tag
His 493	-	expression tag
His 494	-	expression tag
His 495	-	expression tag

R: 0 - 148 (UniProt: P62161)

PDB	External Database	Details
Asp 79	Thr 80	engineered mutation

Contents of the asymmetric unit

Polymers	Number of chains	2
	Total formula weight	29109.9
Non-Polymers*	Number of molecules	3
	Total formula weight	176.2
All*	Total formula weight	29286.1

*Water molecules are not included.