1
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Zhao X, Ma D, Ishiguro K, Saito H, Akichika S, Matsuzawa I, Mito M, Irie T, Ishibashi K, Wakabayashi K, Sakaguchi Y, Yokoyama T, Mishima Y, Shirouzu M, Iwasaki S, Suzuki T, Suzuki T. Glycosylated queuosines in tRNAs optimize translational rate and post-embryonic growth. Cell 2023; 186:5517-5535.e24. [PMID: 37992713 DOI: 10.1016/j.cell.2023.10.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 08/14/2023] [Accepted: 10/26/2023] [Indexed: 11/24/2023]
Abstract
Transfer RNA (tRNA) modifications are critical for protein synthesis. Queuosine (Q), a 7-deaza-guanosine derivative, is present in tRNA anticodons. In vertebrate tRNAs for Tyr and Asp, Q is further glycosylated with galactose and mannose to generate galQ and manQ, respectively. However, biogenesis and physiological relevance of Q-glycosylation remain poorly understood. Here, we biochemically identified two RNA glycosylases, QTGAL and QTMAN, and successfully reconstituted Q-glycosylation of tRNAs using nucleotide diphosphate sugars. Ribosome profiling of knockout cells revealed that Q-glycosylation slowed down elongation at cognate codons, UAC and GAC (GAU), respectively. We also found that galactosylation of Q suppresses stop codon readthrough. Moreover, protein aggregates increased in cells lacking Q-glycosylation, indicating that Q-glycosylation contributes to proteostasis. Cryo-EM of human ribosome-tRNA complex revealed the molecular basis of codon recognition regulated by Q-glycosylations. Furthermore, zebrafish qtgal and qtman knockout lines displayed shortened body length, implying that Q-glycosylation is required for post-embryonic growth in vertebrates.
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Affiliation(s)
- Xuewei Zhao
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan
| | - Ding Ma
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan
| | - Kensuke Ishiguro
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan; Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa 230-0045, Japan
| | - Hironori Saito
- RNA System Biochemistry Laboratory, Cluster for Pioneering Research, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba 277-8561, Japan
| | - Shinichiro Akichika
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan
| | - Ikuya Matsuzawa
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan
| | - Mari Mito
- RNA System Biochemistry Laboratory, Cluster for Pioneering Research, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Toru Irie
- Faculty of Life Sciences, Kyoto Sangyo University, Kita-ku, Kyoto 603-8555, Japan
| | - Kota Ishibashi
- Faculty of Life Sciences, Kyoto Sangyo University, Kita-ku, Kyoto 603-8555, Japan
| | - Kimi Wakabayashi
- Faculty of Life Sciences, Kyoto Sangyo University, Kita-ku, Kyoto 603-8555, Japan
| | - Yuriko Sakaguchi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan
| | - Takeshi Yokoyama
- Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa 230-0045, Japan; Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Yuichiro Mishima
- Faculty of Life Sciences, Kyoto Sangyo University, Kita-ku, Kyoto 603-8555, Japan
| | - Mikako Shirouzu
- Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa 230-0045, Japan
| | - Shintaro Iwasaki
- RNA System Biochemistry Laboratory, Cluster for Pioneering Research, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba 277-8561, Japan
| | - Takeo Suzuki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan.
| | - Tsutomu Suzuki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan.
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2
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Subramanian A, Wang L, Moss T, Voorhies M, Sangwan S, Stevenson E, Pulido EH, Kwok S, Chalkley RJ, Li KH, Krogan NJ, Swaney DL, Burlingame AL, Floor SN, Sil A, Walter P, Mukherjee S. A Legionella toxin exhibits tRNA mimicry and glycosyl transferase activity to target the translation machinery and trigger a ribotoxic stress response. Nat Cell Biol 2023; 25:1600-1615. [PMID: 37857833 PMCID: PMC11005034 DOI: 10.1038/s41556-023-01248-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 09/01/2023] [Indexed: 10/21/2023]
Abstract
A widespread strategy employed by pathogens to establish infection is to inhibit host-cell protein synthesis. Legionella pneumophila, an intracellular bacterial pathogen and the causative organism of Legionnaires' disease, secretes a subset of protein effectors into host cells that inhibit translation elongation. Mechanistic insights into how the bacterium targets translation elongation remain poorly defined. We report here that the Legionella effector SidI functions in an unprecedented way as a transfer-RNA mimic that directly binds to and glycosylates the ribosome. The 3.1 Å cryo-electron microscopy structure of SidI reveals an N-terminal domain with an 'inverted L' shape and surface-charge distribution characteristic of tRNA mimicry, and a C-terminal domain that adopts a glycosyl transferase fold that licenses SidI to utilize GDP-mannose as a sugar precursor. This coupling of tRNA mimicry and enzymatic action endows SidI with the ability to block protein synthesis with a potency comparable to ricin, one of the most powerful toxins known. In Legionella-infected cells, the translational pausing activated by SidI elicits a stress response signature mimicking the ribotoxic stress response, which is activated by elongation inhibitors that induce ribosome collisions. SidI-mediated effects on the ribosome activate the stress kinases ZAKα and p38, which in turn drive an accumulation of the protein activating transcription factor 3 (ATF3). Intriguingly, ATF3 escapes the translation block imposed by SidI, translocates to the nucleus and orchestrates the transcription of stress-inducible genes that promote cell death, revealing a major role for ATF3 in the response to collided ribosome stress. Together, our findings elucidate a novel mechanism by which a pathogenic bacterium employs tRNA mimicry to hijack a ribosome-to-nuclear signalling pathway that regulates cell fate.
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Affiliation(s)
- Advait Subramanian
- G.W. Hooper Foundation, University of California at San Francisco, San Francisco, CA, USA
- Department of Microbiology and Immunology, University of California at San Francisco, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, CA, USA
| | - Lan Wang
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, CA, USA
| | - Tom Moss
- G.W. Hooper Foundation, University of California at San Francisco, San Francisco, CA, USA
- Department of Microbiology and Immunology, University of California at San Francisco, San Francisco, CA, USA
| | - Mark Voorhies
- Department of Microbiology and Immunology, University of California at San Francisco, San Francisco, CA, USA
| | - Smriti Sangwan
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, CA, USA
| | - Erica Stevenson
- Gladstone Institute of Data Science and Biotechnology, J. Gladstone Institutes, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, CA, USA
- Quantitative Biosciences Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Ernst H Pulido
- Gladstone Institute of Data Science and Biotechnology, J. Gladstone Institutes, San Francisco, CA, USA
| | - Samentha Kwok
- Department of Cell and Tissue Biology, University of California at San Francisco, San Francisco, CA, USA
| | - Robert J Chalkley
- Mass Spectrometry Facility, Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, CA, USA
| | - Kathy H Li
- Mass Spectrometry Facility, Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, CA, USA
| | - Nevan J Krogan
- Gladstone Institute of Data Science and Biotechnology, J. Gladstone Institutes, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, CA, USA
- Quantitative Biosciences Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Danielle L Swaney
- Gladstone Institute of Data Science and Biotechnology, J. Gladstone Institutes, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, CA, USA
- Quantitative Biosciences Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Alma L Burlingame
- Mass Spectrometry Facility, Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, CA, USA
| | - Stephen N Floor
- Department of Cell and Tissue Biology, University of California at San Francisco, San Francisco, CA, USA
- Helen Diller Family Comprehensive Cancer Center, University of California at San Francisco, San Francisco, CA, USA
| | - Anita Sil
- Department of Microbiology and Immunology, University of California at San Francisco, San Francisco, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Peter Walter
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, CA, USA.
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA.
- Bay Area Institute of Science, Altos Labs, Redwood City, CA, USA.
| | - Shaeri Mukherjee
- G.W. Hooper Foundation, University of California at San Francisco, San Francisco, CA, USA.
- Department of Microbiology and Immunology, University of California at San Francisco, San Francisco, CA, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
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3
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Hassan BA, Milicaj J, Ramirez-Mondragon CA, Sham YY, Taylor EA. Ligand-Induced Conformational and Dynamical Changes in a GT-B Glycosyltransferase: Molecular Dynamics Simulations of Heptosyltransferase I Complexes. J Chem Inf Model 2022; 62:324-339. [PMID: 34967618 PMCID: PMC8864558 DOI: 10.1021/acs.jcim.1c00868] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Understanding the dynamical motions and ligand recognition motifs of heptosyltransferase I (HepI) can be critical to discerning the behavior of other glycosyltransferase (GT) enzymes. Prior studies in our lab have demonstrated that GTs in the GT-B structural class, which are characterized by their connection of two Rossman-like domains by a linker region, have conserved structural fold and dynamical motions, despite low sequence homology, therefore making discoveries found in HepI transferable to other GT-B enzymes. Through molecular dynamics simulations and ligand binding free energy analysis of HepI in the apo and bound complexes (for all kinetically relevant combinations of the native substrates/products), we have determined the energetically favored enzymatic pathway for ligand binding and release. Our principal component, dynamic cross correlation, and network analyses of the simulations have revealed correlated motions involving residues within the N-terminal domain communicating with C-terminal domain residues via both proximal amino acid residues and also functional groups of the bound substrates. Analyses of the structural changes, energetics of substrate/product binding, and changes in pKa have elucidated a variety of inter and intradomain interactions that are critical for enzyme catalysis. These data corroborate our experimental observations of protein conformational changes observed in both presteady state kinetic and circular dichroism analyses of HepI. These simulations provided invaluable structural insights into the regions involved in HepI conformational rearrangement upon ligand binding. Understanding the specific interactions governing conformational changes is likely to enhance our efforts to develop novel dynamics disrupting inhibitors against GT-B structural enzymes in the future.
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Affiliation(s)
- Bakar A. Hassan
- Department of Chemistry, Wesleyan University, Middletown, Connecticut 06459, United States
| | - Jozafina Milicaj
- Department of Chemistry, Wesleyan University, Middletown, Connecticut 06459, United States
| | - Carlos Andres Ramirez-Mondragon
- Department of Integrative Biology and Physiology, Medical School and Bioinformatics and Computational Biology Program, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Yuk Yin Sham
- Department of Integrative Biology and Physiology, Medical School and Bioinformatics and Computational Biology Program, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Erika A. Taylor
- Department of Chemistry, Wesleyan University, Middletown, Connecticut 06459, United States
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4
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Paudel S, Wachira J, McCarthy PC. Towards Computationally Guided Design and Engineering of a Neisseria meningitidis Serogroup W Capsule Polymerase with Altered Substrate Specificity. Processes (Basel) 2021; 9:2192. [PMID: 37483532 PMCID: PMC10361700 DOI: 10.3390/pr9122192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2023] Open
Abstract
Heavy metal contamination of drinking water is a public health concern that requires the development of more efficient bioremediation techniques. Absorption technologies, including biosorption, provide opportunities for improvements to increase the diversity of target metal ions and overall binding capacity. Microorganisms are a key component in wastewater treatment plants, and they naturally bind metal ions through surface macromolecules but with limited capacity. The long-term goal of this work is to engineer capsule polymerases to synthesize molecules with novel functionalities. In previously published work, we showed that the Neisseria meningitidis serogroup W (NmW) galactose-sialic acid (Gal-NeuNAc) heteropolysaccharide binds lead ions effectively, thereby demonstrating the potential for its use in environmental decontamination applications. In this study, computational analysis of the NmW capsule polymerase galactosyltransferase (GT) domain was used to gain insight into how the enzyme could be modified to enable the synthesis of N-acetylgalactosamine-sialic acid (GalNAc-NeuNAc) heteropolysaccharide. Various computational approaches, including molecular modeling with I-TASSER and molecular dynamics (MD) simulations with NAMD, were utilized to identify key amino acid residues in the substrate binding pocket of the GT domain that may be key to conferring UDP-GalNAc specificity. Through these combined strategies and using BshA, a UDP-GlcNAc transferase, as a structural template, several NmW active site residues were identified as mutational targets to accommodate the proposed N-acetyl group in UDP-GalNAc. Thus, a rational approach for potentially conferring new properties to bacterial capsular polysaccharides is demonstrated.
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Affiliation(s)
- Subhadra Paudel
- Department of Computer Science, Morgan State University, Baltimore, MD 21251, USA
| | - James Wachira
- Department of Biology, Morgan State University, Baltimore, MD 21251, USA
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5
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Royer CJ, Cook PD. A structural and functional analysis of the glycosyltransferase BshA from Staphylococcus aureus: Insights into the reaction mechanism and regulation of bacillithiol production. Protein Sci 2019; 28:1083-1094. [PMID: 30968475 DOI: 10.1002/pro.3617] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 04/05/2019] [Accepted: 04/08/2019] [Indexed: 01/20/2023]
Abstract
Bacillithiol is a glucosamine-derived antioxidant found in several pathogenic Gram-positive bacteria. The compound is involved in maintaining the appropriate redox state within the cell as well as detoxifying foreign agents like the antibiotic fosfomycin. Bacillithiol is produced via the action of three enzymes, including BshA, a retaining GT-B glycosyltransferase that utilizes UDP-N-acetylglucosamine and l-malate to produce N-acetylglucosaminyl-malate. Recent studies suggest that retaining GT-B glycosyltransferases like BshA utilize a substrate-assisted mechanism that goes through an SN i-like transition state. In a previous study, we relied on X-ray crystallography as well as computational simulations to hypothesize the manner in which substrates would bind the enzyme, but several questions about substrate binding and the role of one of the amino acid residues persisted. Another study demonstrated that BshA might be subject to feedback inhibition by bacillithiol, but this phenomenon was not analyzed further to determine the exact mechanism of inhibition. Here we present X-ray crystallographic structures and steady-state kinetics results that help elucidate both of these issues. Our ligand-bound crystal structures demonstrate that the active site provides an appropriate steric and geometric arrangement of ligands to facilitate the substrate-assisted mechanism. Finally, we show that bacillithiol is competitive for UDP-N-acetylglucosamine with a Ki value near 120-130 μM and likely binds within the BshA active site, suggesting that bacillithiol modulates BshA activity via feedback inhibition. The work presented here furthers our understanding of bacillithiol metabolism and can aid in the development of inhibitors to counteract resistance to antibiotics such as fosfomycin.
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Affiliation(s)
| | - Paul D Cook
- Department of Chemistry, Grand Valley State University, Allendale, Michigan
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6
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Gagnon SML, Legg MSG, Sindhuwinata N, Letts JA, Johal AR, Schuman B, Borisova SN, Palcic MM, Peters T, Evans SV. High-resolution crystal structures and STD NMR mapping of human ABO(H) blood group glycosyltransferases in complex with trisaccharide reaction products suggest a molecular basis for product release. Glycobiology 2018; 27:966-977. [PMID: 28575295 DOI: 10.1093/glycob/cwx053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 05/31/2017] [Indexed: 11/12/2022] Open
Abstract
The human ABO(H) blood group A- and B-synthesizing glycosyltransferases GTA and GTB have been structurally characterized to high resolution in complex with their respective trisaccharide antigen products. These findings are particularly timely and relevant given the dearth of glycosyltransferase structures collected in complex with their saccharide reaction products. GTA and GTB utilize the same acceptor substrates, oligosaccharides terminating with α-l-Fucp-(1→2)-β-d-Galp-OR (where R is a glycolipid or glycoprotein), but use distinct UDP donor sugars, UDP-N-acetylgalactosamine and UDP-galactose, to generate the blood group A (α-l-Fucp-(1→2)[α-d-GalNAcp-(1→3)]-β-d-Galp-OR) and blood group B (α-l-Fucp-(1→2)[α-d-Galp-(1→3)]-β-d-Galp-OR) determinant structures, respectively. Structures of GTA and GTB in complex with their respective trisaccharide products reveal a conflict between the transferred sugar monosaccharide and the β-phosphate of the UDP donor. Mapping of the binding epitopes by saturation transfer difference NMR measurements yielded data consistent with the X-ray structural results. Taken together these data suggest a mechanism of product release where monosaccharide transfer to the H-antigen acceptor induces active site disorder and ejection of the UDP leaving group prior to trisaccharide egress.
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Affiliation(s)
- Susannah M L Gagnon
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6
| | - Max S G Legg
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6
| | - Nora Sindhuwinata
- Institute of Chemistry, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - James A Letts
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6
| | - Asha R Johal
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6
| | - Brock Schuman
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6
| | - Svetlana N Borisova
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6
| | - Monica M Palcic
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6.,Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Thomas Peters
- Institute of Chemistry, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Stephen V Evans
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6
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7
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Abstract
SIGNIFICANCE Since the discovery and structural characterization of bacillithiol (BSH), the biochemical functions of BSH-biosynthesis enzymes (BshA/B/C) and BSH-dependent detoxification enzymes (FosB, Bst, GlxA/B) have been explored in Bacillus and Staphylococcus species. It was shown that BSH plays an important role in detoxification of reactive oxygen and electrophilic species, alkylating agents, toxins, and antibiotics. Recent Advances: More recently, new functions of BSH were discovered in metal homeostasis (Zn buffering, Fe-sulfur cluster, and copper homeostasis) and virulence control in Staphylococcus aureus. Unexpectedly, strains of the S. aureus NCTC8325 lineage were identified as natural BSH-deficient mutants. Modern mass spectrometry-based approaches have revealed the global reach of protein S-bacillithiolation in Firmicutes as an important regulatory redox modification under hypochlorite stress. S-bacillithiolation of OhrR, MetE, and glyceraldehyde-3-phosphate dehydrogenase (Gap) functions, analogous to S-glutathionylation, as both a redox-regulatory device and in thiol protection under oxidative stress. CRITICAL ISSUES Although the functions of the bacilliredoxin (Brx) pathways in the reversal of S-bacillithiolations have been recently addressed, significantly more work is needed to establish the complete Brx reduction pathway, including the major enzyme(s), for reduction of oxidized BSH (BSSB) and the targets of Brx action in vivo. FUTURE DIRECTIONS Despite the large number of identified S-bacillithiolated proteins, the physiological relevance of this redox modification was shown for only selected targets and should be a subject of future studies. In addition, many more BSH-dependent detoxification enzymes are evident from previous studies, although their roles and biochemical mechanisms require further study. This review of BSH research also pin-points these missing gaps for future research. Antioxid. Redox Signal. 28, 445-462.
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Affiliation(s)
- Pete Chandrangsu
- 1 Department of Microbiology, Cornell University , Ithaca, New York
| | - Vu Van Loi
- 2 Institute for Biology-Microbiology , Freie Universität Berlin, Berlin, Germany
| | - Haike Antelmann
- 2 Institute for Biology-Microbiology , Freie Universität Berlin, Berlin, Germany
| | - John D Helmann
- 1 Department of Microbiology, Cornell University , Ithaca, New York
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8
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Ramírez AS, Boilevin J, Mehdipour AR, Hummer G, Darbre T, Reymond JL, Locher KP. Structural basis of the molecular ruler mechanism of a bacterial glycosyltransferase. Nat Commun 2018; 9:445. [PMID: 29386647 PMCID: PMC5792488 DOI: 10.1038/s41467-018-02880-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Accepted: 01/02/2018] [Indexed: 11/09/2022] Open
Abstract
The membrane-associated, processive and retaining glycosyltransferase PglH from Campylobacter jejuni is part of the biosynthetic pathway of the lipid-linked oligosaccharide (LLO) that serves as the glycan donor in bacterial protein N-glycosylation. Using an unknown counting mechanism, PglH catalyzes the transfer of exactly three α1,4 N-acetylgalactosamine (GalNAc) units to the growing LLO precursor, GalNAc-α1,4-GalNAc-α1,3-Bac-α1-PP-undecaprenyl. Here, we present crystal structures of PglH in three distinct states, including a binary complex with UDP-GalNAc and two ternary complexes containing a chemo-enzymatically generated LLO analog and either UDP or synthetic, nonhydrolyzable UDP-CH2-GalNAc. PglH contains an amphipathic helix ("ruler helix") that has a dual role of facilitating membrane attachment and glycan counting. The ruler helix contains three positively charged side chains that can bind the pyrophosphate group of the LLO substrate and thus limit the addition of GalNAc units to three. These results, combined with molecular dynamics simulations, provide the mechanism of glycan counting by PglH.
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Affiliation(s)
- Ana S Ramírez
- Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH), CH-8093, Zürich, Switzerland
| | - Jérémy Boilevin
- Department of Chemistry and Biochemistry, University of Berne, CH-3012, Berne, Switzerland
| | - Ahmad Reza Mehdipour
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, DE-60438, Frankfurt, Germany
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, DE-60438, Frankfurt, Germany.,Institute of Biophysics, Goethe University, DE-60438, Frankfurt, Germany
| | - Tamis Darbre
- Department of Chemistry and Biochemistry, University of Berne, CH-3012, Berne, Switzerland
| | - Jean-Louis Reymond
- Department of Chemistry and Biochemistry, University of Berne, CH-3012, Berne, Switzerland
| | - Kaspar P Locher
- Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH), CH-8093, Zürich, Switzerland.
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9
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Guo Y, Wang L, Guo J, Gu G, Guo Z. Biochemical studies of inositol N-acetylglucosaminyltransferase involved in mycothiol biosynthesis in Corynebacterium diphtheria. Org Biomol Chem 2017; 15:3775-3782. [DOI: 10.1039/c7ob00555e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
First-time expression, isolation, biochemical characterization, and mutagenesis studies of a MshA from Corynebacterium diphtheria involved in its mycothiol biosynthesis.
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Affiliation(s)
- Yuchuan Guo
- National Glycoengineering Research Center and Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology
- Shandong University
- Jinan 250100
- China
- Department of Chemistry
| | - Lizhen Wang
- National Glycoengineering Research Center and Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology
- Shandong University
- Jinan 250100
- China
| | - Jiatong Guo
- Department of Chemistry
- University of Florida
- Gainesville
- USA
| | - Guofeng Gu
- National Glycoengineering Research Center and Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology
- Shandong University
- Jinan 250100
- China
| | - Zhongwu Guo
- Department of Chemistry
- University of Florida
- Gainesville
- USA
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