Our most recent work has focused on the determination of preferred nucleic acid and/or protein substrates of RapA. Excess RapA was previously shown to produce complex effects on in vitro transcription , which included inhibitory effects at ' early ' timepoints and a significant increase in the number of completed transcriptional rounds in prolonged in vitro transcription reactions , which was attributed to RapAs remodeling of DNA - RNA polymerase - RNA ternary complexes ( 23 ) . In this study - given that the interaction of RapA with the polymerase is well established - using primarily purified native RapA ( 21 ) at a ' physiological ' ( 1:1 ) molar ratio with the polymerase , we have conducted experiments in order to clarify the general mechanistic aspects of this remodeling . Our work presents multiple , independent lines of evidence indicating that RNA is a key substrate of RapA. Our biochemical data , supported by a homology model of the RapA NTPase domain - DNA complex , suggest that this RNA - remodeling activity of RapA may be in addition to its DNA - binding activity . Our results are consistent with a model in which RapA promotes RNA release from DNA - RNA polymerase - RNA ternary complexes . Taken together , our data indicate a novel RNA remodeling activity for RapA , a representative of the SWI / SNF protein superfamily . This finding could potentially deepen our understanding of the functions of all SWI / SNF proteins , and may point to yetunidentified activities of eukaryotic SWI / SNF proteins .