RNA size is a critical factor for U-containing substrate selectivity and permanent pseudouridylated product release during the RNA:ψ-synthase reaction catalyzed by box H/ACA sRNP enzyme at high temperature
Tillault A.-S.,Biopole Of Luniversite Of Lorraine |
Tillault A.-S.,University of Lethbridge |
Fourmann J.-B.,Biopole Of Luniversite Of Lorraine |
Fourmann J.-B.,Max Planck Institute for Biophysical Chemistry |
And 5 more authors.
Biochimie | Year: 2015
The box H/ACA small ribonucleoprotein particles (H/ACA sRNPs) are RNP enzymes that isomerize uridines (U) into pseudouridines (ψ) in archaeal RNAs. The RNA component acts as a guide by forming base-pair interactions with the substrate RNA to specify the target nucleotide of the modification to the catalytic subunit Cbf5. Here, we have analyzed association of an H/ACA sRNP enzyme from the hyperthermophilic archaeon Pyrococcus abyssi with synthetic substrate RNAs of different length and with target nucleotide variants, and estimated their turnover at high temperature. In these conditions, we found that a short substrate, which length is restricted to the interaction with RNA guide sequence, has higher turnover rate. However, the longer substrate with additional 5′ and 3′ sequences non-complementary to the guide RNA is better discriminated by the U to ψ conversion allowing the RNP enzyme to distinguish the modified product from the substrate. In addition, we identified that the conserved residue Y179 in the catalytic center of Cbf5 is crucial for substrate selectivity. © 2015 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM). All rights reserved.
Ji W.-Y.,Zhejiang University |
Feng L.-F.,Zhejiang University |
Zhang C.-L.,Zhejiang University |
Hoppe S.,CNRS Reactions and Process Engineering Laboratory |
And 3 more authors.
AIChE Journal | Year: 2016
Significance: A concept called reactive compatibilizer-tracer is proposed. The latter bears reactive groups capable of reacting with its counterpart on forming a copolymer for in situ compatibilization, and fluorescent labels allowing determining very small amounts of the in situ formed compatibilizer and formation of micelles when it occurs. Owing to this concept, it is shown that a reactive compatibilizer may be very efficient at the beginning of a reactive blending process and may suddenly become completely inefficient, resulting in an abrupt and drastic increase in size of the dispersed phase domains. © 2015 American Institute of Chemical Engineers.
Spenkuch F.,Johannes Gutenberg University Mainz |
Motorin Y.,Biopole Of Luniversite Of Lorraine |
Helm M.,Johannes Gutenberg University Mainz
RNA Biology | Year: 2014
Pseudouridine (Ψ) is the most abundant of >150 nucleoside modifications in RNA. Although C was discovered as the first modified nucleoside more than half a century ago, neither the enzymatic mechanism of its formation, nor the function of this modification are fully elucidated. We present the consistent picture of Ψ synthases, their substrates and their substrate positions in model organisms of all domains of life as it has emerged to date and point out the challenges that remain concerning higher eukaryotes and the elucidation of the enzymatic mechanism. © 2014 Taylor & Francis Group, LLC.