3J7H

Structure of beta-galactosidase at 3.2-A resolution obtained by cryo-electron microscopy

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	Beta-galactosidase	polymer	1024	116602.5	4	UniProt (P00722) Pfam (PF02837) Pfam (PF00703) Pfam (PF02836) Pfam (PF16353) Pfam (PF02929) In PDB	Escherichia coli K-12	Beta-gal, Lactase
2	A, B, C, D	MAGNESIUM ION	non-polymer		24.3	4	Chemie (MG)

Contents of the asymmetric unit

Polymers	Number of chains	4
	Total formula weight	466409.9
Non-Polymers*	Number of molecules	4
	Total formula weight	97.2
All*	Total formula weight	466507.2

*Water molecules are not included.