1
|
Klein MA, Wild K, Kišonaitė M, Sinning I. Methionine aminopeptidase 2 and its autoproteolysis product have different binding sites on the ribosome. Nat Commun 2024; 15:716. [PMID: 38267453 PMCID: PMC10808355 DOI: 10.1038/s41467-024-44862-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 01/04/2024] [Indexed: 01/26/2024] Open
Abstract
Excision of the initiator methionine is among the first co-translational processes that occur at the ribosome. While this crucial step in protein maturation is executed by two types of methionine aminopeptidases in eukaryotes (MAP1 and MAP2), additional roles in disease and translational regulation have drawn more attention to MAP2. Here, we report several cryo-EM structures of human and fungal MAP2 at the 80S ribosome. Irrespective of nascent chains, MAP2 can occupy the tunnel exit. On nascent chain displaying ribosomes, the MAP2-80S interaction is highly dynamic and the MAP2-specific N-terminal extension engages in stabilizing interactions with the long rRNA expansion segment ES27L. Loss of this extension by autoproteolytic cleavage impedes interactions at the tunnel, while promoting MAP2 to enter the ribosomal A-site, where it engages with crucial functional centers of translation. These findings reveal that proteolytic remodeling of MAP2 severely affects ribosome binding, and set the stage for targeted functional studies.
Collapse
Affiliation(s)
- Marius A Klein
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - Klemens Wild
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - Miglė Kišonaitė
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany.
| |
Collapse
|
2
|
Zhang M, He S, Han X, Cui J, Wang H, Huo X, Yan F, Feng L, Wang C, Ma X. Discovery of Potential Antituberculosis Agents Targeted Methionine Aminopeptidase 1 of Mycobacterium tuberculosis by the Developed Fluorescent Probe. Anal Chem 2023; 95:16210-16215. [PMID: 37899593 DOI: 10.1021/acs.analchem.3c02952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2023]
Abstract
Tuberculosis (TB) is a chronic systemic infectious disease caused by Mycobacterium tuberculosis (M. tuberculosis). Methionine aminopeptidase 1 (MtMET-AP1) is a hydrolase that mediates the necessary post-translational N-terminal methionine excision (NME) of peptides during protein synthesis, which is necessary for bacterial proliferation and is a potential target for the treatment of tuberculosis. Based on the functional characteristics of MtMET-AP1, we developed an enzymatic activated near-infrared fluorescent probe DDAN-MT for rapid, highly selective, and real-time monitoring of endogenous MtMET-AP1 activity in M. tuberculosis. Using the probe DDAN-MT, a visually high-throughput screening technique was established, which obtained three potential inhibitors (GSK-J4 hydrochchloride, JX06, and lavendustin C) against MtMET-AP1 from a 2560 compounds library. More importantly, these inhibitors could inhibit the growth of M. tuberculosis H37Ra especially (MICs < 5 μM), with low toxicities on intestinal bacteria strains and human cells. Therefore, the visual sensing of MtMET-AP1 was successfully performed by DDAN-MT, and MtMET-AP1 inhibitors were discovered as potential antituberculosis agents.
Collapse
Affiliation(s)
- Ming Zhang
- Second Affiliated Hospital, Dalian Medical University, Dalian 116044, China
- Dalian Key Laboratory of Metabolic Target Characterization and Traditional Chinese Medicine Intervention, College of Integrative Medicine, College of Pharmacy, Dalian Medical University, Dalian 116044, China
| | - Shengui He
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
| | - Xiuyan Han
- Second Affiliated Hospital, Dalian Medical University, Dalian 116044, China
| | - Jingnan Cui
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
| | - Honglei Wang
- Dalian Key Laboratory of Metabolic Target Characterization and Traditional Chinese Medicine Intervention, College of Integrative Medicine, College of Pharmacy, Dalian Medical University, Dalian 116044, China
| | - Xiaokui Huo
- Second Affiliated Hospital, Dalian Medical University, Dalian 116044, China
| | - Fei Yan
- Second Affiliated Hospital, Dalian Medical University, Dalian 116044, China
| | - Lei Feng
- Second Affiliated Hospital, Dalian Medical University, Dalian 116044, China
- School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, China
| | - Chao Wang
- Second Affiliated Hospital, Dalian Medical University, Dalian 116044, China
- Dalian Key Laboratory of Metabolic Target Characterization and Traditional Chinese Medicine Intervention, College of Integrative Medicine, College of Pharmacy, Dalian Medical University, Dalian 116044, China
| | - Xiaochi Ma
- Second Affiliated Hospital, Dalian Medical University, Dalian 116044, China
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou 221004, China
| |
Collapse
|
3
|
Bögeholz LA, Mercier E, Wintermeyer W, Rodnina MV. Deformylation of nascent peptide chains on the ribosome. Methods Enzymol 2023; 684:39-70. [DOI: 10.1016/bs.mie.2023.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
|
4
|
McGrath H, Černeková M, Kolář MH. Binding of the peptide deformylase on the ribosome surface modulates the exit tunnel interior. Biophys J 2022; 121:4443-4451. [PMID: 36335428 PMCID: PMC9748369 DOI: 10.1016/j.bpj.2022.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 08/26/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022] Open
Abstract
Proteosynthesis on ribosomes is regulated at many levels. Conformational changes of the ribosome, possibly induced by external factors, may transfer over large distances and contribute to the regulation. The molecular principles of this long-distance allostery within the ribosome remain poorly understood. Here, we use structural analysis and atomistic molecular dynamics simulations to investigate peptide deformylase (PDF), an enzyme that binds to the ribosome surface near the ribosomal protein uL22 during translation and chemically modifies the emerging nascent peptide. Our simulations of the entire ribosome-PDF complex reveal that the PDF undergoes a swaying motion on the ribosome surface at the submicrosecond timescale. We show that the PDF affects the conformational dynamics of parts of the ribosome over distances of more than 5 nm. Using a supervised-learning algorithm, we demonstrate that the exit tunnel is influenced by the presence or absence of PDF. Our findings suggest a possible effect of the PDF on the nascent peptide translocation through the ribosome exit tunnel.
Collapse
Affiliation(s)
- Hugo McGrath
- Department of Physical Chemistry, University of Chemistry and Technology, Prague, Czech Republic
| | - Michaela Černeková
- Department of Physical Chemistry, University of Chemistry and Technology, Prague, Czech Republic
| | - Michal H Kolář
- Department of Physical Chemistry, University of Chemistry and Technology, Prague, Czech Republic.
| |
Collapse
|
5
|
Mercier E, Wang X, Bögeholz LAK, Wintermeyer W, Rodnina MV. Cotranslational Biogenesis of Membrane Proteins in Bacteria. Front Mol Biosci 2022; 9:871121. [PMID: 35573737 PMCID: PMC9099147 DOI: 10.3389/fmolb.2022.871121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 04/12/2022] [Indexed: 12/26/2022] Open
Abstract
Nascent polypeptides emerging from the ribosome during translation are rapidly scanned and processed by ribosome-associated protein biogenesis factors (RPBs). RPBs cleave the N-terminal formyl and methionine groups, assist cotranslational protein folding, and sort the proteins according to their cellular destination. Ribosomes translating inner-membrane proteins are recognized and targeted to the translocon with the help of the signal recognition particle, SRP, and SRP receptor, FtsY. The growing nascent peptide is then inserted into the phospholipid bilayer at the translocon, an inner-membrane protein complex consisting of SecY, SecE, and SecG. Folding of membrane proteins requires that transmembrane helices (TMs) attain their correct topology, the soluble domains are inserted at the correct (cytoplasmic or periplasmic) side of the membrane, and – for polytopic membrane proteins – the TMs find their interaction partner TMs in the phospholipid bilayer. This review describes the recent progress in understanding how growing nascent peptides are processed and how inner-membrane proteins are targeted to the translocon and find their correct orientation at the membrane, with the focus on biophysical approaches revealing the dynamics of the process. We describe how spontaneous fluctuations of the translocon allow diffusion of TMs into the phospholipid bilayer and argue that the ribosome orchestrates cotranslational targeting not only by providing the binding platform for the RPBs or the translocon, but also by helping the nascent chains to find their correct orientation in the membrane. Finally, we present the auxiliary role of YidC as a chaperone for inner-membrane proteins. We show how biophysical approaches provide new insights into the dynamics of membrane protein biogenesis and raise new questions as to how translation modulates protein folding.
Collapse
|
6
|
Yang CI, Kim J, Shan SO. Ribosome-nascent chain interaction regulates N-terminal protein modification. J Mol Biol 2022; 434:167535. [PMID: 35278477 PMCID: PMC9126151 DOI: 10.1016/j.jmb.2022.167535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 03/01/2022] [Accepted: 03/04/2022] [Indexed: 01/02/2023]
Abstract
Numerous proteins initiate their folding, localization, and modifications early during translation, and emerging data show that the ribosome actively participates in diverse protein biogenesis pathways. Here we show that the ribosome imposes an additional layer of substrate selection during N-terminal methionine excision (NME), an essential protein modification in bacteria. Biochemical analyses show that cotranslational NME is exquisitely sensitive to a hydrophobic signal sequence or transmembrane domain near the N terminus of the nascent polypeptide. The ability of the nascent chain to access the active site of NME enzymes dictates NME efficiency, which is inhibited by confinement of the nascent chain on the ribosome surface and exacerbated by signal recognition particle. In vivo measurements corroborate the inhibition of NME by an N-terminal hydrophobic sequence, suggesting the retention of formylmethionine on a substantial fraction of the secretory and membrane proteome. Our work demonstrates how molecular features of a protein regulate its cotranslational modification and highlights the active participation of the ribosome in protein biogenesis pathways via interactions of the ribosome surface with the nascent protein.
Collapse
|
7
|
Bögeholz LAK, Mercier E, Wintermeyer W, Rodnina MV. Kinetic control of nascent protein biogenesis by peptide deformylase. Sci Rep 2021; 11:24457. [PMID: 34961771 PMCID: PMC8712518 DOI: 10.1038/s41598-021-03969-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 12/13/2021] [Indexed: 12/05/2022] Open
Abstract
Synthesis of bacterial proteins on the ribosome starts with a formylated methionine. Removal of the N-terminal formyl group is essential and is carried out by peptide deformylase (PDF). Deformylation occurs co-translationally, shortly after the nascent-chain emerges from the ribosomal exit tunnel, and is necessary to allow for further N-terminal processing. Here we describe the kinetic mechanism of deformylation by PDF of ribosome-bound nascent-chains and show that PDF binding to and dissociation from ribosomes is rapid, allowing for efficient scanning of formylated substrates in the cell. The rate-limiting step in the PDF mechanism is a conformational rearrangement of the nascent-chain that takes place after cleavage of the formyl group. Under conditions of ongoing translation, the nascent-chain is deformylated rapidly as soon as it becomes accessible to PDF. Following deformylation, the enzyme is slow in releasing the deformylated nascent-chain, thereby delaying further processing and potentially acting as an early chaperone that protects short nascent chains before they reach a length sufficient to recruit other protein biogenesis factors.
Collapse
Affiliation(s)
- Lena A K Bögeholz
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, 37077, Göttingen, Germany
| | - Evan Mercier
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, 37077, Göttingen, Germany
| | - Wolfgang Wintermeyer
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, 37077, Göttingen, Germany
| | - Marina V Rodnina
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, 37077, Göttingen, Germany.
| |
Collapse
|
8
|
Koubek J, Schmitt J, Galmozzi CV, Kramer G. Mechanisms of Cotranslational Protein Maturation in Bacteria. Front Mol Biosci 2021; 8:689755. [PMID: 34113653 PMCID: PMC8185961 DOI: 10.3389/fmolb.2021.689755] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/10/2021] [Indexed: 01/05/2023] Open
Abstract
Growing cells invest a significant part of their biosynthetic capacity into the production of proteins. To become functional, newly-synthesized proteins must be N-terminally processed, folded and often translocated to other cellular compartments. A general strategy is to integrate these protein maturation processes with translation, by cotranslationally engaging processing enzymes, chaperones and targeting factors with the nascent polypeptide. Precise coordination of all factors involved is critical for the efficiency and accuracy of protein synthesis and cellular homeostasis. This review provides an overview of the current knowledge on cotranslational protein maturation, with a focus on the production of cytosolic proteins in bacteria. We describe the role of the ribosome and the chaperone network in protein folding and how the dynamic interplay of all cotranslationally acting factors guides the sequence of cotranslational events. Finally, we discuss recent data demonstrating the coupling of protein synthesis with the assembly of protein complexes and end with a brief discussion of outstanding questions and emerging concepts in the field of cotranslational protein maturation.
Collapse
Affiliation(s)
- Jiří Koubek
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Jaro Schmitt
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Carla Veronica Galmozzi
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Günter Kramer
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
| |
Collapse
|
9
|
Dautin N. Folding Control in the Path of Type 5 Secretion. Toxins (Basel) 2021; 13:341. [PMID: 34064645 PMCID: PMC8151025 DOI: 10.3390/toxins13050341] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/04/2021] [Accepted: 05/05/2021] [Indexed: 12/17/2022] Open
Abstract
The type 5 secretion system (T5SS) is one of the more widespread secretion systems in Gram-negative bacteria. Proteins secreted by the T5SS are functionally diverse (toxins, adhesins, enzymes) and include numerous virulence factors. Mechanistically, the T5SS has long been considered the simplest of secretion systems, due to the paucity of proteins required for its functioning. Still, despite more than two decades of study, the exact process by which T5SS substrates attain their final destination and correct conformation is not totally deciphered. Moreover, the recent addition of new sub-families to the T5SS raises additional questions about this secretion mechanism. Central to the understanding of type 5 secretion is the question of protein folding, which needs to be carefully controlled in each of the bacterial cell compartments these proteins cross. Here, the biogenesis of proteins secreted by the Type 5 secretion system is discussed, with a focus on the various factors preventing or promoting protein folding during biogenesis.
Collapse
Affiliation(s)
- Nathalie Dautin
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, Université de Paris, LBPC-PM, CNRS, UMR7099, 75005 Paris, France;
- Institut de Biologie Physico-Chimique, Fondation Edmond de Rothschild pour le Développement de la Recherche Scientifique, 75005 Paris, France
| |
Collapse
|
10
|
Akbar S, Bhakta S, Sengupta J. Structural insights into the interplay of protein biogenesis factors with the 70S ribosome. Structure 2021; 29:755-767.e4. [PMID: 33761323 DOI: 10.1016/j.str.2021.03.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 02/16/2021] [Accepted: 03/02/2021] [Indexed: 11/28/2022]
Abstract
Bacterial co-translational N-terminal methionine excision, an early event of nascent polypeptide chain processing, is mediated by two enzymes: peptide deformylase (PDF) and methionine aminopeptidase (MetAP). Trigger factor (TF), the only ribosome-associated bacterial chaperone, offers co-translational chaperoning assistance. Here, we present two high-resolution cryoelectron microscopy structures of tRNA-bound E. coli ribosome complexes showing simultaneous binding of PDF and TF, in the absence (3.4 Å) and presence of MetAP (4.1 Å). These structures establish molecular details of the interactions of the factors with the ribosome, and thereby reveal the structural basis of nascent chain processing. Our results suggest that simultaneous binding of all three factors is not a functionally favorable mechanism of nascent chain processing. Strikingly, an unusual structural distortion of the 70S ribosome, potentially driven by binding of multiple copies of MetAP, is observed when MetAP is incubated with a pre-formed PDF-TF-bound ribosome complex.
Collapse
Affiliation(s)
- Shirin Akbar
- Structural Biology & Bio-Informatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata 700 032, India
| | - Sayan Bhakta
- Structural Biology & Bio-Informatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata 700 032, India
| | - Jayati Sengupta
- Structural Biology & Bio-Informatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata 700 032, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
| |
Collapse
|
11
|
Wild K, Aleksić M, Lapouge K, Juaire KD, Flemming D, Pfeffer S, Sinning I. MetAP-like Ebp1 occupies the human ribosomal tunnel exit and recruits flexible rRNA expansion segments. Nat Commun 2020; 11:776. [PMID: 32034140 PMCID: PMC7005732 DOI: 10.1038/s41467-020-14603-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 01/20/2020] [Indexed: 12/13/2022] Open
Abstract
Human Ebp1 is a member of the proliferation-associated 2G4 (PA2G4) family and plays an important role in cancer regulation. Ebp1 shares the methionine aminopeptidase (MetAP) fold and binds to mature 80S ribosomes for translational control. Here, we present a cryo-EM single particle analysis reconstruction of Ebp1 bound to non-translating human 80S ribosomes at a resolution range from 3.3 to ~8 Å. Ebp1 blocks the tunnel exit with major interactions to the general uL23/uL29 docking site for nascent chain-associated factors complemented by eukaryote-specific eL19 and rRNA helix H59. H59 is defined as dynamic adaptor undergoing significant remodeling upon Ebp1 binding. Ebp1 recruits rRNA expansion segment ES27L to the tunnel exit via specific interactions with rRNA consensus sequences. The Ebp1-ribosome complex serves as a template for MetAP binding and provides insights into the structural principles for spatial coordination of co-translational events and molecular triage at the ribosomal tunnel exit. The ErbB3 receptor binding protein Ebp1 binds to ribosomes and is linked to translational control. Here, the authors present the cryo-EM structure of human Ebp1 bound to a non-translating 80S ribosome and find that Ebp1 blocks the tunnel exit and recruits the rRNA expansion segment ES27L to the tunnel exit.
Collapse
Affiliation(s)
- Klemens Wild
- Biochemiezentrum der Universität Heidelberg (BZH), INF 328, D-69120, Heidelberg, Germany
| | - Milan Aleksić
- Zentrum für Molekulare Biologie der Universität Heidelberg, INF282, D-69120, Heidelberg, Germany
| | - Karine Lapouge
- Biochemiezentrum der Universität Heidelberg (BZH), INF 328, D-69120, Heidelberg, Germany
| | - Keven D Juaire
- Biochemiezentrum der Universität Heidelberg (BZH), INF 328, D-69120, Heidelberg, Germany
| | - Dirk Flemming
- Biochemiezentrum der Universität Heidelberg (BZH), INF 328, D-69120, Heidelberg, Germany
| | - Stefan Pfeffer
- Zentrum für Molekulare Biologie der Universität Heidelberg, INF282, D-69120, Heidelberg, Germany.
| | - Irmgard Sinning
- Biochemiezentrum der Universität Heidelberg (BZH), INF 328, D-69120, Heidelberg, Germany.
| |
Collapse
|
12
|
Yang CI, Hsieh HH, Shan SO. Timing and specificity of cotranslational nascent protein modification in bacteria. Proc Natl Acad Sci U S A 2019; 116:23050-23060. [PMID: 31666319 PMCID: PMC6859321 DOI: 10.1073/pnas.1912264116] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The nascent polypeptide exit site of the ribosome is a crowded environment where multiple ribosome-associated protein biogenesis factors (RPBs) compete for the nascent polypeptide to influence their localization, folding, or quality control. Here we address how N-terminal methionine excision (NME), a ubiquitous process crucial for the maturation of over 50% of the bacterial proteome, occurs in a timely and selective manner in this crowded environment. In bacteria, NME is mediated by 2 essential enzymes, peptide deformylase (PDF) and methionine aminopeptidase (MAP). We show that the reaction of MAP on ribosome-bound nascent chains approaches diffusion-limited rates, allowing immediate methionine excision of optimal substrates after deformylation. Specificity is achieved by kinetic competition of NME with translation elongation and by regulation from other RPBs, which selectively narrow the processing time window for suboptimal substrates. A mathematical model derived from the data accurately predicts cotranslational NME efficiency in the cytosol. Our results demonstrate how a fundamental enzymatic activity is reshaped by its associated macromolecular environment to optimize both efficiency and selectivity, and provides a platform to study other cotranslational protein biogenesis pathways.
Collapse
Affiliation(s)
- Chien-I Yang
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Hao-Hsuan Hsieh
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Shu-Ou Shan
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| |
Collapse
|