[1] NCI, Lab Metab, NIH, Bethesda, MD 20892 USA
[2] Clarassance Inc, Rockville, MD USA
[3] Leidos Biomed Res Inc, Prot Express Lab, Frederick Natl Lab Canc Res, Frederick, MD USA
[4] NCI, Prot Struct Sect, Macromol Crystallog Lab, Frederick, MD 21701 USA