Fig. 3: The tRNA-chaperoned assembly cycle.
From: tRNA as an assembly chaperone for a macromolecular transcription-processing complex
A model of the tRNA-chaperoned assembly cycle was derived from biochemical and structural data of this study and is illustrated by solved and available atomic structures, the latter of which are labeled with their PDB codes. tRNA refers to tRNAGln/Arg. Assembly intermediates, shown as accessible molecular surface, are labeled according to their appearance during the assembly cycle: I1, core vRNAP (PDB 6RIC); I2*, metastable core vRNAP–tRNA (no experimental structure available); I3, core vRNAP–tRNAGln/Arg–E11–NPH-I; I4, complete vRNAP–VETF-s/l; I5, complete vRNAP lacking the capping enzyme (complete vRNAP–D1/D12). The starting point is minimal vRNAP and the endpoint is PIC on an early promoter (PDB 7AMV). *Transient intermediate that can be detected only by biochemical means (Fig. 1b, bottom, gradient profile 2). #Conformational change in the tRNA assembly chaperone.
