Decomposing bulk signals to reveal hidden information in processive enzyme reactions

A case study in mRNA translation

authored by
Nadin Haase, Wolf Holtkamp, Simon Christ, Dag Heinemann, Marina V. Rodnina, Sophia Rudorf
Abstract

Processive enzymes like polymerases or ribosomes are often studied in bulk experiments by monitoring time-dependent signals, such as fluorescence time traces. However, due to biomolecular process stochasticity, ensemble signals may lack the distinct features of single-molecule signals. Here, we demonstrate that, under certain conditions, bulk signals from processive reactions can be decomposed to unveil hidden information about individual reaction steps. Using mRNA translation as a case study, we show that decomposing a noisy ensemble signal generated by the translation of mRNAs with more than a few codons is an ill-posed problem, addressable through Tikhonov regularization. We apply our method to the fluorescence signatures of in-vitro translated LepB mRNA and determine codon-position dependent translation rates and corresponding state-specific fluorescence intensities. We find a significant change in fluorescence intensity after the fourth and the fifth peptide bond formation, and show that both codon position and encoded amino acid have an effect on the elongation rate. This demonstrates that our approach enhances the information content extracted from bulk experiments, thereby expanding the range of these time- and cost-efficient methods.

Organisation(s)
Institute of Cell Biology and Biophysics
Department of Computational Biology
Institute of Horticultural Production Systems
External Organisation(s)
Max-Planck Institute for Multidisciplinary Sciences
Paul-Ehrlich-Institut (PEI) - Federal Institute for Vaccines and Biomedicines
Type
Article
Journal
PLoS Computational Biology
Volume
20
ISSN
1553-734X
Publication date
05.03.2024
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Ecology, Evolution, Behavior and Systematics, Modelling and Simulation, Ecology, Molecular Biology, Genetics, Cellular and Molecular Neuroscience, Computational Theory and Mathematics
Electronic version(s)
https://doi.org/10.1101/2023.05.17.541147 (Access: Open)
https://doi.org/10.1371/journal.pcbi.1011918 (Access: Open)