Loading Rho to terminate transcription.
In bacteria, one of the major transcriptional termination mechanisms requires a hexameric RNA/DNA helicase known as Rho. One question that has remained unanswered is how the helicase loads onto a nascent transcript so that it can initiate actions on the transcript to cause termination. Recent structures of Rho bound to nucleic acid by show how the individual RNA-binding domains of the 6 subunits are organized and that the ring is split open. The opening is wide enough to accommodate single-stranded RNA and suggests that this conformation is poised to load onto mRNA.
Richardson
John P
JP
Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, IN 47405, USA. richardj@indiana.edu
D001665:Binding Sites / Q000235:genetics; D004277:DNA, Single-Stranded / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D017434:Protein Structure, Tertiary; D020365:RNA Helicases / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012234:Rho Factor / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D013728:Terminator Regions, Genetic; D014158:Transcription, Genetic
D004277:DNA, Single-Stranded; D012333:RNA, Messenger; D012234:Rho Factor; D012321:DNA-Directed RNA Polymerases; D020365:RNA Helicases