2R20

Structure of the RNA brominated tridecamer r(GCGUU-5BUGAAACGC) at 1.3 A (Br2)

Entity

Entity ID	Chain ID	Description	Type	Chain length	Formula weight	Number of molecules	DB Name (Accession)	Biological source	Descriptive keywords
1	A, B (A, B)	RNA (5'-R(*GP*CP*GP*UP*UP*(5BU)P*GP*AP*AP*AP*CP*GP*C)-3')	polymer	13	4236.4	2
2	C, D, E, G, H (A, B)	SODIUM ION	non-polymer		23.0	5	Chemie (NA)
3	F (A)	MAGNESIUM ION	non-polymer		24.3	1	Chemie (MG)
4	I, J (A, B)	water	water		18.0	165	Chemie (HOH)

Contents of the asymmetric unit

Polymers	Number of chains	2
	Total formula weight	8472.8
Non-Polymers*	Number of molecules	6
	Total formula weight	139.3
All*	Total formula weight	8612.1

*Water molecules are not included.