1XX1

Structural basis for ion-coordination and the catalytic mechanism of sphingomyelinases D

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)	Sphingomyelinase I	polymer	285	32083.0	4	UniProt (Q8I914)	Loxosceles laeta	SMase I
2	BA, CA, DA, E, EA... (D, A, B, C)	SULFATE ION	non-polymer		96.1	23	Chemie (SO4)
3	GA, K, S, Z (D, A, B, C)	MAGNESIUM ION	non-polymer		24.3	4	Chemie (MG)
4	AA, HA, L (C, D, A)	4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID	non-polymer		238.3	3	Chemie (EPE)
5	IA, JA, KA, LA (A, B, C, D)	water	water		18.0	1018	Chemie (HOH)

Contents of the asymmetric unit

Polymers	Number of chains	4
	Total formula weight	128331.8
Non-Polymers*	Number of molecules	30
	Total formula weight	3021.6
All*	Total formula weight	131353.4

*Water molecules are not included.