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González-Faune P, Sánchez-Arévalo I, Sarkar S, Majhi K, Bandopadhyay R, Cabrera-Barjas G, Gómez A, Banerjee A. Computational Study on Temperature Driven Structure-Function Relationship of Polysaccharide Producing Bacterial Glycosyl Transferase Enzyme. Polymers (Basel) 2021; 13:1771. [PMID: 34071348 DOI: 10.3390/polym13111771] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 05/24/2021] [Accepted: 05/26/2021] [Indexed: 12/12/2022] Open
Abstract
Glycosyltransferase (GTs) is a wide class of enzymes that transfer sugar moiety, playing a key role in the synthesis of bacterial exopolysaccharide (EPS) biopolymer. In recent years, increased demand for bacterial EPSs has been observed in pharmaceutical, food, and other industries. The application of the EPSs largely depends upon their thermal stability, as any industrial application is mainly reliant on slow thermal degradation. Keeping this in context, EPS producing GT enzymes from three different bacterial sources based on growth temperature (mesophile, thermophile, and hyperthermophile) are considered for in silico analysis of the structural–functional relationship. From the present study, it was observed that the structural integrity of GT increases significantly from mesophile to thermophile to hyperthermophile. In contrast, the structural plasticity runs in an opposite direction towards mesophile. This interesting temperature-dependent structural property has directed the GT–UDP-glucose interactions in a way that thermophile has finally demonstrated better binding affinity (−5.57 to −10.70) with an increased number of hydrogen bonds (355) and stabilizing amino acids (Phe, Ala, Glu, Tyr, and Ser). The results from this study may direct utilization of thermophile-origin GT as best for industrial-level bacterial polysaccharide production.
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Plassart L, Shayan R, Montellese C, Rinaldi D, Larburu N, Pichereaux C, Froment C, Lebaron S, O'Donohue MF, Kutay U, Marcoux J, Gleizes PE, Plisson-Chastang C. The final step of 40S ribosomal subunit maturation is controlled by a dual key lock. eLife 2021; 10:61254. [PMID: 33908345 PMCID: PMC8112863 DOI: 10.7554/elife.61254] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 04/19/2021] [Indexed: 12/31/2022] Open
Abstract
Preventing premature interaction of pre-ribosomes with the translation apparatus is essential for translational accuracy. Hence, the final maturation step releasing functional 40S ribosomal subunits, namely processing of the 18S ribosomal RNA 3' end, is safeguarded by the protein DIM2, which both interacts with the endoribonuclease NOB1 and masks the rRNA cleavage site. To elucidate the control mechanism that unlocks NOB1 activity, we performed cryo-electron microscopy analysis of late human pre-40S particles purified using a catalytically inactive form of the ATPase RIO1. These structures, together with in vivo and in vitro functional analyses, support a model in which ATP-loaded RIO1 cooperates with ribosomal protein RPS26/eS26 to displace DIM2 from the 18S rRNA 3' end, thereby triggering final cleavage by NOB1; release of ADP then leads to RIO1 dissociation from the 40S subunit. This dual key lock mechanism requiring RIO1 and RPS26 guarantees the precise timing of pre-40S particle conversion into translation-competent ribosomal subunits.
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Affiliation(s)
- Laura Plassart
- Molecular, Cellular and Developmental Biology department (MCD), Centre de Biologie Integrative (CBI), University of Toulouse, CNRS, UPS, Toulouse, France
| | - Ramtin Shayan
- Molecular, Cellular and Developmental Biology department (MCD), Centre de Biologie Integrative (CBI), University of Toulouse, CNRS, UPS, Toulouse, France
| | | | - Dana Rinaldi
- Molecular, Cellular and Developmental Biology department (MCD), Centre de Biologie Integrative (CBI), University of Toulouse, CNRS, UPS, Toulouse, France
| | - Natacha Larburu
- Molecular, Cellular and Developmental Biology department (MCD), Centre de Biologie Integrative (CBI), University of Toulouse, CNRS, UPS, Toulouse, France
| | - Carole Pichereaux
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Carine Froment
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Simon Lebaron
- Molecular, Cellular and Developmental Biology department (MCD), Centre de Biologie Integrative (CBI), University of Toulouse, CNRS, UPS, Toulouse, France
| | - Marie-Françoise O'Donohue
- Molecular, Cellular and Developmental Biology department (MCD), Centre de Biologie Integrative (CBI), University of Toulouse, CNRS, UPS, Toulouse, France
| | - Ulrike Kutay
- Institut für Biochemie, ETH Zürich, Zurich, Switzerland
| | - Julien Marcoux
- Institut de Pharmacologie et Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Pierre-Emmanuel Gleizes
- Molecular, Cellular and Developmental Biology department (MCD), Centre de Biologie Integrative (CBI), University of Toulouse, CNRS, UPS, Toulouse, France
| | - Celia Plisson-Chastang
- Molecular, Cellular and Developmental Biology department (MCD), Centre de Biologie Integrative (CBI), University of Toulouse, CNRS, UPS, Toulouse, France
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Lin Y, Deepak RNVK, Zheng JZ, Fan H, Zheng L. A dual substrate-accessing mechanism of a major facilitator superfamily protein facilitates lysophospholipid flipping across the cell membrane. J Biol Chem 2018; 293:19919-19931. [PMID: 30373772 DOI: 10.1074/jbc.ra118.005548] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 10/23/2018] [Indexed: 11/06/2022] Open
Abstract
Lysophospholipid transporter (LplT) is a member of the major facilitator superfamily present in many Gram-negative bacteria. LplT catalyzes flipping of lysophospholipids (LPLs) across the bacterial inner membrane, playing an important role in bacterial membrane homeostasis. We previously reported that LplT promotes both uptake of exogenous LPLs and intramembranous LPL flipping across the bilayer. To gain mechanistic insight into this dual LPL-flipping activity, here we implemented a combination of computational approaches and LPL transport analyses to study LPL binding of and translocation by LplT. Our results suggest that LplT translocates LPLs through an elongated cavity exhibiting an extremely asymmetric polarity. We found that two D(E)N motifs form a head group-binding site, in which the carboxylate group of Asp-30 is important for LPL head group recognition. Substitutions of residues in the head group-binding site disrupted both LPL uptake and flipping activities. However, alteration of hydrophobic residues on the interface between the N- and C-terminal domains impaired LPL flipping specifically, resulting in LPLs accumulation in the membrane, but LPL uptake remained active. These results suggest a dual substrate-accessing mechanism, in which LplT recruits LPLs to its substrate-binding site via two routes, either from its extracellular entry or through a membrane-embedded groove between transmembrane helices, and then moves them toward the inner membrane leaflet. This LPL-flipping mechanism is likely conserved in many bacterial species, and our findings illustrate how LplT adjusts the major facilitator superfamily translocation pathway to perform its versatile lipid homeostatic functions.
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Affiliation(s)
- Yibin Lin
- From the Department of Biochemistry and Molecular Biology, Center for Membrane Biology, the University of Texas Health Science Center at Houston McGovern Medical School, Houston Texas 77030
| | - R N V Krishna Deepak
- the Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), 138671 Singapore, and
| | - Jonathan Zixiang Zheng
- From the Department of Biochemistry and Molecular Biology, Center for Membrane Biology, the University of Texas Health Science Center at Houston McGovern Medical School, Houston Texas 77030
| | - Hao Fan
- the Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), 138671 Singapore, and .,the Department of Biological Sciences (DBS), National University of Singapore, 117558 Singapore, and Center for Computational Biology, DUKE-NUS Medical School, 169857 Singapore
| | - Lei Zheng
- From the Department of Biochemistry and Molecular Biology, Center for Membrane Biology, the University of Texas Health Science Center at Houston McGovern Medical School, Houston Texas 77030,
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Shanata JAP, Frazier SJ, Lester HA, Dougherty DA. Using mutant cycle analysis to elucidate long-range functional coupling in allosteric receptors. Methods Mol Biol 2012; 796:97-113. [PMID: 22052487 PMCID: PMC4006985 DOI: 10.1007/978-1-61779-334-9_6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Functional coupling of residues that are far apart in space is the quintessential property of allosteric receptors. Data from functional studies of allosteric receptors, such as whole-cell dose-response relations, can be used to determine if mutation to a receptor significantly impacts agonist potency. However, the classification of perturbations as primarily impacting binding or allosteric function is more challenging, often requiring detailed kinetic studies. This protocol describes a simple strategy, derived from mutant cycle analysis, for elucidating long-range functional coupling in allosteric receptors (ELFCAR). Introduction of a gain-of-function reporter mutation, followed by a mutant cycle analysis of the readily measured macroscopic EC(50) values can provide insight into the role of many physically distant targets. This new method should find broad application in determining the functional roles of residues in allosteric receptors.
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Affiliation(s)
- Jai A. P. Shanata
- Divisions of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Blvd., Pasadena, CA 91125
| | - Shawnalea J. Frazier
- Division of Biology, California Institute of Technology, 1200 East California Blvd., Pasadena, CA 91125
| | - Henry A. Lester
- Division of Biology, California Institute of Technology, 1200 East California Blvd., Pasadena, CA 91125
| | - Dennis A. Dougherty
- Divisions of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Blvd., Pasadena, CA 91125
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