1TO2

crystal structure of the complex of subtilisin BPN' with chymotrypsin inhibitor 2 M59K, in pH 9 cryosoak

Entity

Entity ID	Chain ID	Description	Type	Chain length	Formula weight	Number of molecules	DB Name (Accession)	Biological source	Descriptive keywords
1	A (E)	Subtilisin BPN'	polymer	281	28381.4	1	UniProt (P00782) Pfam (PF00082)	Bacillus amyloliquefaciens	Subtilisin Novo, Alkaline protease
2	B (I)	chymotrypsin inhibitor 2	polymer	64	7281.6	1	UniProt (Q40059) Pfam (PF00280)	Hordeum vulgare subsp. vulgare (domesticated barley)
3	C (E)	CALCIUM ION	non-polymer		40.1	1	Chemie (CA)
4	D (E)	SODIUM ION	non-polymer		23.0	1	Chemie (NA)
5	E, F (E)	CITRIC ACID	non-polymer		192.1	2	Chemie (CIT)
6	G, H, I (E)	POLYETHYLENE GLYCOL (N=34)	non-polymer		1529.8	3	Chemie (15P)
7	J, K (E, I)	water	water		18.0	449	Chemie (HOH)

Sequence modifications

E: 1 - 275 (UniProt: P00782)

PDB	External Database	Details
His 276	-	expression tag
His 277	-	expression tag
His 278	-	expression tag
His 279	-	expression tag
His 280	-	expression tag
His 281	-	expression tag

I: 21 - 83 (UniProt: Q40059)

PDB	External Database	Details
Met 20	-	initiating methionine
Lys 59	Met 60	engineered mutation

Contents of the asymmetric unit

Polymers	Number of chains	2
	Total formula weight	35663.0
Non-Polymers*	Number of molecules	7
	Total formula weight	5036.8
All*	Total formula weight	40699.8

*Water molecules are not included.