scholarly journals Ribosome elongation kinetics of consecutively charged residues are coupled to electrostatic force

2021 ◽  
Author(s):  
Sarah E Leininger ◽  
Judith Rodriguez ◽  
Quyen V Vu ◽  
Yang Jiang ◽  
Ma Suan Li ◽  
...  
Keyword(s):  
Amino Acid ◽  
Conformational Changes ◽  
Electrostatic Force ◽  
Ribosome Profiling ◽  
Peptide Bond Formation ◽  
Translation Speed ◽  
Charged Residues ◽  
Nascent Chain ◽  
Chain Conformations

The speed of protein synthesis can dramatically change when consecutively charged residues are incorporated into an elongating nascent protein by the ribosome. The molecular origins of this class of allosteric coupling remain unknown. We demonstrate, using multi-scale simulations, that positively charged residues generate large forces that pull the P-site amino acid away from the A-site amino acid. Negatively charged residues generate forces of similar magnitude but opposite direction. And that these conformational changes, respectively, raise and lower the transition state barrier height to peptide bond formation, explaining how charged residues mechanochemically alter translation speed. This mechanochemical mechanism is consistent with in vivo ribosome profiling data exhibiting a proportionality between translation speed and the number of charged residues, experimental data characterizing nascent chain conformations, and a previously published cryo-EM structure of a ribosome-nascent chain complex containing consecutive lysines. These results expand the role of mechanochemistry in translation, and provide a framework for interpreting experimental results on translation speed.

scholarly journals Integrated in vivo and in vitro nascent chain profiling reveals widespread translational pausing

2016 ◽  
Vol 113 (7) ◽  
pp. E829-E838 ◽  
Author(s):  
Yuhei Chadani ◽  
Tatsuya Niwa ◽  
Shinobu Chiba ◽  
Hideki Taguchi ◽  
Koreaki Ito
Keyword(s):  
Escherichia Coli ◽  
Membrane Proteins ◽  
Ribosome Profiling ◽  
Cytosolic Proteins ◽  
Nascent Polypeptide ◽  
Nascent Chain ◽  
Chemical Trait

Although the importance of the nonuniform progression of elongation in translation is well recognized, there have been few attempts to explore this process by directly profiling nascent polypeptides, the relevant intermediates of translation. Such approaches will be essential to complement other approaches, including ribosome profiling, which is extremely powerful but indirect with respect to the actual translation processes. Here, we use the nascent polypeptide's chemical trait of having a covalently attached tRNA moiety to detect translation intermediates. In a case study,Escherichia coliSecA was shown to undergo nascent polypeptide-dependent translational pauses. We then carried out integrated in vivo and in vitro nascent chain profiling (iNP) to characterize 1,038 proteome members ofE.colithat were encoded by the first quarter of the chromosome with respect to their propensities to accumulate polypeptidyl–tRNA intermediates. A majority of them indeed undergo single or multiple pauses, some occurring only in vitro, some occurring only in vivo, and some occurring both in vivo and in vitro. Thus, translational pausing can be intrinsically robust, subject to in vivo alleviation, or require in vivo reinforcement. Cytosolic and membrane proteins tend to experience different classes of pauses; membrane proteins often pause multiple times in vivo. We also note that the solubility of cytosolic proteins correlates with certain categories of pausing. Translational pausing is widespread and diverse in nature.

scholarly journals Ribosomal stalling landscapes revealed by high-throughput inverse toeprinting of mRNA libraries

2018 ◽  
Vol 1 (5) ◽  
pp. e201800148 ◽  
Author(s):  
Britta Seip ◽  
Guénaël Sacheau ◽  
Denis Dupuy ◽  
C Axel Innis
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
High Throughput ◽  
Quantitative Measure ◽  
Ribosome Profiling ◽  
Coding Region ◽  
Versatile Tool

Although it is known that the amino acid sequence of a nascent polypeptide can impact its rate of translation, dedicated tools to systematically investigate this process are lacking. Here, we present high-throughput inverse toeprinting, a method to identify peptide-encoding transcripts that induce ribosomal stalling in vitro. Unlike ribosome profiling, inverse toeprinting protects the entire coding region upstream of a stalled ribosome, making it possible to work with random or focused transcript libraries that efficiently sample the sequence space. We used inverse toeprinting to characterize the stalling landscapes of free and drug-boundEscherichia coliribosomes, obtaining a comprehensive list of arrest motifs that were validated in vivo, along with a quantitative measure of their pause strength. Thanks to the modest sequencing depth and small amounts of material required, inverse toeprinting provides a highly scalable and versatile tool to study sequence-dependent translational processes.

scholarly journals Distinct stages of the translation elongation cycle revealed by sequencing ribosome-protected mRNA fragments

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Liana F Lareau ◽  
Dustin H Hite ◽  
Gregory J Hogan ◽  
Patrick O Brown
Keyword(s):  
Amino Acid ◽  
Conformational Changes ◽  
Structural Rearrangements ◽  
Cycle Sequencing ◽  
Translation Speed ◽  
Translation Elongation ◽  
Elongation Cycle ◽  
Specific Elongation ◽  
Detailed Kinetics ◽  
Kinetics Of

During translation elongation, the ribosome ratchets along its mRNA template, incorporating each new amino acid and translocating from one codon to the next. The elongation cycle requires dramatic structural rearrangements of the ribosome. We show here that deep sequencing of ribosome-protected mRNA fragments reveals not only the position of each ribosome but also, unexpectedly, its particular stage of the elongation cycle. Sequencing reveals two distinct populations of ribosome footprints, 28–30 nucleotides and 20–22 nucleotides long, representing translating ribosomes in distinct states, differentially stabilized by specific elongation inhibitors. We find that the balance of small and large footprints varies by codon and is correlated with translation speed. The ability to visualize conformational changes in the ribosome during elongation, at single-codon resolution, provides a new way to study the detailed kinetics of translation and a new probe with which to identify the factors that affect each step in the elongation cycle.

scholarly journals Ribosome occupancy profiles are conserved between structurally and evolutionarily related yeast domains

2021 ◽  
Author(s):  
Daniel A Nissley ◽  
Anna Carbery ◽  
Mark Chonofsky ◽  
Charlotte M Deane
Keyword(s):  
Amino Acid ◽  
Large Scale ◽  
Sequence Similarity ◽  
Ribosome Profiling ◽  
Supplementary Information ◽  
Rare Codon ◽  
Homologous Proteins ◽  
Translation Speed ◽  
And Function ◽  
Related Proteins

Abstract Motivation Protein synthesis is a non-equilibrium process, meaning that the speed of translation can influence the ability of proteins to fold and function. Assuming that structurally similar proteins fold by similar pathways, the profile of translation speed along an mRNA should be evolutionarily conserved between related proteins to direct correct folding and downstream function. The only evidence to date for such conservation of translation speed between homologous proteins has used codon rarity as a proxy for translation speed. There are, however, many other factors including mRNA structure and the chemistry of the amino acids in the A- and P-sites of the ribosome that influence the speed of amino acid addition. Results Ribosome profiling experiments provide a signal directly proportional to the underlying translation times at the level of individual codons. We compared ribosome occupancy profiles (extracted from five different large-scale yeast ribosome profiling studies) between related protein domains to more directly test if their translation schedule was conserved. Our analysis reveals that the ribosome occupancy profiles of paralogous domains tend to be significantly more similar to one another than to profiles of non-paralogous domains. This trend does not depend on domain length, structural classes, amino acid composition or sequence similarity. Our results indicate that entire ribosome occupancy profiles and not just rare codon locations are conserved between even distantly related domains in yeast, providing support for the hypothesis that translation schedule is conserved between structurally related domains to retain folding pathways and facilitate efficient folding. Availability and implementation Python3 code is available on GitHub at https://github.com/DanNissley/Compare-ribosome-occupancy. Supplementary information Supplementary data are available at Bioinformatics online.

Structural basis for amino-acid recognition and transmembrane signalling by tandem Per–Arnt–Sim (tandem PAS) chemoreceptor sensory domains

2015 ◽  
Vol 71 (10) ◽  
pp. 2127-2136 ◽  
Author(s):  
Yu C. Liu ◽  
Mayra A. Machuca ◽  
Simone A. Beckham ◽  
Menachem J. Gunzburg ◽  
Anna Roujeinikova
Keyword(s):  
Amino Acid ◽  
Ligand Binding ◽  
Conformational Changes ◽  
Transmembrane Helix ◽  
Crystallographic Analysis ◽  
Structural Basis ◽  
Bacterial Populations ◽  
Piston Displacement ◽  
Downward Displacement

Chemotaxis, mediated by methyl-accepting chemotaxis protein (MCP) receptors, plays an important role in the ecology of bacterial populations. This paper presents the first crystallographic analysis of the structure and ligand-induced conformational changes of the periplasmic tandem Per-Arnt-Sim (PAS) sensing domain (PTPSD) of a characterized MCP chemoreceptor. Analysis of the complex of theCampylobacter jejuniTlp3 PTPSD with isoleucine (a chemoattractant) revealed that the PTPSD is a dimer in the crystal. The two ligand-binding sites are located in the membrane-distal PAS domains on the faces opposite to the dimer interface. Mutagenesis experiments show that the five strongly conserved residues that stabilize the main-chain moiety of isoleucine are essential for binding, suggesting that the mechanism by which this family of chemoreceptors recognizes amino acids is highly conserved. Although the fold and mode of ligand binding of the PTPSD are different from the aspartic acid receptor Tar, the structural analysis suggests that the PTPSDs of amino-acid chemoreceptors are also likely to signal by a piston displacement mechanism. The PTPSD fluctuates between piston (C-terminal helix) `up' and piston `down' states. Binding of an attractant to the distal PAS domain locks it in the closed form, weakening its association with the proximal domain and resulting in the transition of the latter into an open form, concomitant with a downward (towards the membrane) 4 Å piston displacement of the C-terminal helix.In vivo, this movement would generate a transmembrane signal by driving a downward displacement of the transmembrane helix 2 towards the cytoplasm.

scholarly journals Proline codon pair selection determines ribosome pausing strength and translation efficiency in bacteria

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Ralph Krafczyk ◽  
Fei Qi ◽  
Alina Sieber ◽  
Judith Mehler ◽  
Kirsten Jung ◽  
...  
Keyword(s):  
Amino Acid ◽  
Mrna Level ◽  
Mrna Translation ◽  
Peptide Bond ◽  
Translation Efficiency ◽  
Peptide Bond Formation ◽  
Copy Numbers ◽  
Nascent Chain ◽  
Ribosome Pausing ◽  
Codon Pairs

AbstractThe speed of mRNA translation depends in part on the amino acid to be incorporated into the nascent chain. Peptide bond formation is especially slow with proline and two adjacent prolines can even cause ribosome stalling. While previous studies focused on how the amino acid context of a Pro-Pro motif determines the stalling strength, we extend this question to the mRNA level. Bioinformatics analysis of the Escherichia coli genome revealed significantly differing codon usage between single and consecutive prolines. We therefore developed a luminescence reporter to detect ribosome pausing in living cells, enabling us to dissect the roles of codon choice and tRNA selection as well as to explain the genome scale observations. Specifically, we found a strong selective pressure against CCC/U-C, a sequon causing ribosomal frameshifting even under wild-type conditions. On the other hand, translation efficiency as positive evolutionary driving force led to an overrepresentation of CCG. This codon is not only translated the fastest, but the corresponding prolyl-tRNA reaches almost saturating levels. By contrast, CCA, for which the cognate prolyl-tRNA amounts are limiting, is used to regulate pausing strength. Thus, codon selection both in discrete positions but especially in proline codon pairs can tune protein copy numbers.

scholarly journals Ribosome pausing, a dangerous necessity for co-translational events

2019 ◽  
Vol 48 (3) ◽  
pp. 1043-1055 ◽  
Author(s):  
Martine A Collart ◽  
Benjamin Weiss
Keyword(s):  
Protein Interactions ◽  
Protein Targeting ◽  
Regulation Of Gene Expression ◽  
Ribosome Profiling ◽  
Translation Elongation ◽  
Cellular Compartment ◽  
Nascent Chain ◽  
The Right ◽  
Ribosome Pausing

Abstract In recent years translation elongation has emerged as an important contributor to the regulation of gene expression. There are multiple quality control checkpoints along the way of producing mature proteins and targeting them to the right cellular compartment, or associating them correctly with their partners. Ribosomes pause to allow co-translational protein folding, protein targeting or protein interactions, and the pausing is dictated by a combination of the mRNA sequence and structure, the tRNA availability and the nascent peptide. However, ribosome pausing can also lead to ribosome collisions and co-translational degradation of both mRNA and nascent chain. Understanding how the translating ribosome tunes the different maturation steps that nascent proteins must undergo, what the timing of these maturation events is, and how degradation can be avoided when pausing is needed, is now possible by the emergence of methods to follow ribosome dynamics in vivo. This review summarizes some of the recent studies that have advanced our knowledge about co-translational events using the power of ribosome profiling, and some of the questions that have emerged from these studies.

CarR, a MarR-family regulator from Corynebacterium glutamicum, modulated antibiotic and aromatic compound resistance

2019 ◽  
Vol 476 (21) ◽  
pp. 3141-3159 ◽  
Author(s):  
Meiru Si ◽  
Can Chen ◽  
Zengfan Wei ◽  
Zhijin Gong ◽  
GuiZhi Li ◽  
...  
Keyword(s):  
Stress Response ◽  
Ligand Binding ◽  
Corynebacterium Glutamicum ◽  
Conformational Changes ◽  
Cysteine Oxidation ◽  
Transcriptional Regulatory ◽  
Ligand Free ◽  
Redox Sensing

Abstract MarR (multiple antibiotic resistance regulator) proteins are a family of transcriptional regulators that is prevalent in Corynebacterium glutamicum. Understanding the physiological and biochemical function of MarR homologs in C. glutamicum has focused on cysteine oxidation-based redox-sensing and substrate metabolism-involving regulators. In this study, we characterized the stress-related ligand-binding functions of the C. glutamicum MarR-type regulator CarR (C. glutamicum antibiotic-responding regulator). We demonstrate that CarR negatively regulates the expression of the carR (ncgl2886)–uspA (ncgl2887) operon and the adjacent, oppositely oriented gene ncgl2885, encoding the hypothetical deacylase DecE. We also show that CarR directly activates transcription of the ncgl2882–ncgl2884 operon, encoding the peptidoglycan synthesis operon (PSO) located upstream of carR in the opposite orientation. The addition of stress-associated ligands such as penicillin and streptomycin induced carR, uspA, decE, and PSO expression in vivo, as well as attenuated binding of CarR to operator DNA in vitro. Importantly, stress response-induced up-regulation of carR, uspA, and PSO gene expression correlated with cell resistance to β-lactam antibiotics and aromatic compounds. Six highly conserved residues in CarR were found to strongly influence its ligand binding and transcriptional regulatory properties. Collectively, the results indicate that the ligand binding of CarR induces its dissociation from the carR–uspA promoter to derepress carR and uspA transcription. Ligand-free CarR also activates PSO expression, which in turn contributes to C. glutamicum stress resistance. The outcomes indicate that the stress response mechanism of CarR in C. glutamicum occurs via ligand-induced conformational changes to the protein, not via cysteine oxidation-based thiol modifications.

Sign in / Sign up

Export Citation Format

Share Document