Cover photograph (Copyright © 2008, American Society for Microbiology. All Rights Reserved.): Schematic of the protein components that assemble to form the preinitiation complex at the spliced leader (SL) RNA gene promoter in Trypanosoma brucei. The DNA promoter elements and the transcribed region are shown. The trypanosome SNAP complex consists of the tSNAP50, −42, and −26 subunits. The pseudo-CTD is the carboxy-terminal ∼300 amino acids of the largest subunit of RNA polymerase II and deviates from the canonical heptapeptide repeats present within the yeast and mammalian enzymes. (See related article on page 429.)