397D

A 1.3 A RESOLUTION CRYSTAL STRUCTURE OF THE HIV-1 TRANS-ACTIVATION RESPONSE REGION RNA STEM REVEALS A METAL ION-DEPENDENT BULGE CONFORMATION

Entity

Entity ID	Chain ID	Description	Type	Chain length	Formula weight	Number of molecules	DB Name (Accession)	Biological source	Descriptive keywords
1	A (A)	RNA (5'-R(*GP*GP*CP*CP*AP*GP*AP*UP*CP*UP*GP*AP*GP*CP*G)-3')	polymer	15	4847.0	1
2	B (B)	RNA (5'-R(*GP*CP*UP*CP*UP*CP*UP*GP*GP*CP*CP*C)-3')	polymer	12	3740.2	1
3	C, D, E, F (A)	CALCIUM ION	non-polymer		40.1	4	Chemie (CA)
4	G, H (A, B)	water	water		18.0	178	Chemie (HOH)

Contents of the asymmetric unit

Polymers	Number of chains	2
	Total formula weight	8587.2
Non-Polymers*	Number of molecules	4
	Total formula weight	160.3
All*	Total formula weight	8747.5

*Water molecules are not included.