Crystal structure reveals details of nonstandard RNA transcription

High-resolution crystal structure reveals a new pathway for RNA during a nontraditional form of transcription—the process by which RNA is produced from a DNA template. Caught during the act of reiterative transcription, a form of transcription in which a single base of DNA (represented by the letters A, T, C, and G) codes for several corresponding bases in the RNA (one G in DNA leads to several Gs in the RNA, for example), the new crystal structure reveals RNA exiting the polymerase enzyme through an alternative channel to enable this unconventional mode of transcription.