1ET4

CRYSTAL STRUCTURE OF A VITAMIN B12 BINDING RNA APTAMER WITH LIGAND AT 2.3 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, C, D, E (A, B, C, D, E)	RNA APTAMER, 35-MER	polymer	35	11280.8	5
2	F, G, H, I, J (A, B, C, D, E)	CYANOCOBALAMIN	non-polymer		1356.4	5	Chemie (CNC)
3	K, L, M, N, O (A, B, C, D, E)	water	water		18.0	725	Chemie (HOH)

Contents of the asymmetric unit

Polymers	Number of chains	5
	Total formula weight	56404.1
Non-Polymers*	Number of molecules	5
	Total formula weight	6781.9
All*	Total formula weight	63186.0

*Water molecules are not included.