1XRB

S-adenosylmethionine synthetase (MAT, ATP: L-methionine S-adenosyltransferase, E.C.2.5.1.6) in which MET residues are replaced with selenomethionine residues (MSE)

Entity

Entity ID	Chain ID	Description	Type	Chain length	Formula weight	Number of molecules	DB Name (Accession)	Biological source	Descriptive keywords
1	A	S-ADENOSYLMETHIONINE SYNTHETASE	polymer	383	42289.4	1	UniProt (P04384) Pfam (PF00438) Pfam (PF02772) Pfam (PF02773) UniProt (by SIFTS) (P0A817) In PDB	Escherichia coli	MAT, ATP:L-METHIONINE S-ADENOSYLTRANSFERASE
2	A	PHOSPHATE ION	non-polymer		95.0	2	Chemie (PO4)
3	A	MAGNESIUM ION	non-polymer		24.3	2	Chemie (MG)
4	A	POTASSIUM ION	non-polymer		39.1	2	Chemie (K)

Contents of the asymmetric unit

Polymers	Number of chains	1
	Total formula weight	42289.4
Non-Polymers*	Number of molecules	6
	Total formula weight	316.7
All*	Total formula weight	42606.1

*Water molecules are not included.