title: Transcript-assisted transcriptional proofreading.
abstract: Fidelity of template-dependent nucleic acid synthesis is the main determinant of stable heredity and error-free gene expression. The mechanism (or mechanisms) ensuring fidelity of transcription by DNA-dependent RNA polymerases (RNAPs) is not fully understood. Here, we show that the 3' end-proximal nucleotide of the nascent transcript stimulates hydrolysis of the penultimate phosphodiester bond by providing active groups and coordination bonds to the RNAP active center. This stimulation is much higher in the case of misincorporated nucleotide. We show that during transcription elongation, the hydrolytic reaction stimulated by misincorporated nucleotides proofreads most of the misincorporation events and thus serves as an intrinsic mechanism of transcription fidelity.
authors.affiliation: Waksman Institute, Rutgers University, Piscataway, NJ 08854, USA. nicserzen@mail.ru
authors.forename: Nikolay
authors.initials: N
authors.lastname: Zenkin
authors.forename: Yulia
authors.initials: Y
authors.lastname: Yuzenkova
authors.forename: Konstantin
authors.initials: K
authors.lastname: Severinov
mesh_terms: D000249:Adenosine Monophosphate / Q000378:metabolism; D020029:Base Pairing; D001665:Binding Sites; D002384:Catalysis; D003568:Cytidine Monophosphate / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D006860:Hydrogen Bonding; D006868:Hydrolysis; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism; D008957:Models, Genetic; D009711:Nucleotides / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D013698:Templates, Genetic; D013824:Thermus / Q000201:enzymology; D014158:Transcription, Genetic
chemical_list: D009711:Nucleotides; D012333:RNA, Messenger; D000249:Adenosine Monophosphate; D004247:DNA; D012321:DNA-Directed RNA Polymerases; D003568:Cytidine Monophosphate; D008274:Magnesium