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Sriramoju MK, Ko KT, Hsu STD. Tying a true topological protein knot by cyclization. Biochem Biophys Res Commun 2024; 696:149470. [PMID: 38244314 DOI: 10.1016/j.bbrc.2024.149470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 12/23/2023] [Accepted: 01/03/2024] [Indexed: 01/22/2024]
Abstract
Knotted proteins are fascinating to biophysicists because of their robust ability to fold into intricately defined three-dimensional structures with complex and topologically knotted arrangements. Exploring the biophysical properties of the knotted proteins is of significant interest, as they could offer enhanced chemical, thermal, and mechanostabilities. A true mathematical knot requires a closed path; in contrast, knotted protein structures have open N- and C-termini. To address the question of how a truly knotted protein differs from the naturally occurring counterpart, we enzymatically cyclized a 31 knotted YibK protein from Haemophilus influenza (HiYibK) to investigate the impact of path closure on its structure-function relationship and folding stability. Through the use of a multitude of structural and biophysical tools, including X-ray crystallography, NMR spectroscopy, small angle X-ray scattering, differential scanning calorimetry, and isothermal calorimetry, we showed that the path closure minimally perturbs the native structure and ligand binding of HiYibK. Nevertheless, the cyclization did alter the folding stability and mechanism according to chemical and thermal unfolding analysis. These molecular insights contribute to our fundamental understanding of protein folding and knotting that could have implications in the protein design with higher stabilities.
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Affiliation(s)
| | - Kuang-Ting Ko
- Institute of Biological Chemistry, Academia Sinica, Taipei, 11529, Taiwan
| | - Shang-Te Danny Hsu
- Institute of Biological Chemistry, Academia Sinica, Taipei, 11529, Taiwan; Institute of Biochemical Sciences, National Taiwan University, Taipei, 106319, Taiwan; International Institute for Sustainability with Knotted Chiral Meta Matter (SKCM(2)), Hiroshima University, Higashihiroshima, 739-8527, Japan.
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Hsu MF, Sriramoju MK, Lai CH, Chen YR, Huang JS, Ko TP, Huang KF, Hsu STD. Structure, dynamics, and stability of the smallest and most complex 7 1 protein knot. J Biol Chem 2024; 300:105553. [PMID: 38072060 PMCID: PMC10840475 DOI: 10.1016/j.jbc.2023.105553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 11/21/2023] [Accepted: 12/04/2023] [Indexed: 12/29/2023] Open
Abstract
Proteins can spontaneously tie a variety of intricate topological knots through twisting and threading of the polypeptide chains. Recently developed artificial intelligence algorithms have predicted several new classes of topological knotted proteins, but the predictions remain to be authenticated experimentally. Here, we showed by X-ray crystallography and solution-state NMR spectroscopy that Q9PR55, an 89-residue protein from Ureaplasma urealyticum, possesses a novel 71 knotted topology that is accurately predicted by AlphaFold 2, except for the flexible N terminus. Q9PR55 is monomeric in solution, making it the smallest and most complex knotted protein known to date. In addition to its exceptional chemical stability against urea-induced unfolding, Q9PR55 is remarkably robust to resist the mechanical unfolding-coupled proteolysis by a bacterial proteasome, ClpXP. Our results suggest that the mechanical resistance against pulling-induced unfolding is determined by the complexity of the knotted topology rather than the size of the molecule.
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Affiliation(s)
- Min-Feng Hsu
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | | | - Chih-Hsuan Lai
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Yun-Ru Chen
- Academia Sinica Protein Clinic, Academia Sinica, Taipei, Taiwan
| | - Jing-Siou Huang
- Academia Sinica Protein Clinic, Academia Sinica, Taipei, Taiwan
| | - Tzu-Ping Ko
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Kai-Fa Huang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan; Academia Sinica Protein Clinic, Academia Sinica, Taipei, Taiwan
| | - Shang-Te Danny Hsu
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan; Academia Sinica Protein Clinic, Academia Sinica, Taipei, Taiwan; Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan; International Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM(2)), Hiroshima University, Higashihiroshima, Japan.
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Hou MH, Wang YC, Yang CS, Liao KF, Chang JW, Shih O, Yeh YQ, Sriramoju MK, Weng TW, Jeng US, Hsu STD, Chen Y. Structural insights into the regulation, ligand recognition, and oligomerization of bacterial STING. Nat Commun 2023; 14:8519. [PMID: 38129386 PMCID: PMC10739871 DOI: 10.1038/s41467-023-44052-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 11/28/2023] [Indexed: 12/23/2023] Open
Abstract
The cyclic GMP-AMP synthase (cGAS)/stimulator of interferon gene (STING) signaling pathway plays a critical protective role against viral infections. Metazoan STING undergoes multilayers of regulation to ensure specific signal transduction. However, the mechanisms underlying the regulation of bacterial STING remain unclear. In this study, we determined the crystal structure of anti-parallel dimeric form of bacterial STING, which keeps itself in an inactive state by preventing cyclic dinucleotides access. Conformational transition between inactive and active states of bacterial STINGs provides an on-off switch for downstream signaling. Some bacterial STINGs living in extreme environment contain an insertion sequence, which we show codes for an additional long lid that covers the ligand-binding pocket. This lid helps regulate anti-phage activities. Furthermore, bacterial STING can bind cyclic di-AMP in a triangle-shaped conformation via a more compact ligand-binding pocket, forming spiral-shaped protofibrils and higher-order fibril filaments. Based on the differences between cyclic-dinucleotide recognition, oligomerization, and downstream activation of different bacterial STINGs, we proposed a model to explain structure-function evolution of bacterial STINGs.
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Grants
- National Science and Technology Council, Taiwan, 109-2311-B241-001 National Science and Technology Council, Taiwan, 111-2311-B-039-001-MY3
- National Science and Technology Council, Taiwan, 111-2811-M-001-125
- National Science and Technology Council, Taiwan, 110-2113-M-001-050-MY3 National Science and Technology Council, Taiwan, 110-2311-B-001-013-MY3 Academia Sinica intramural fund, an Academia Sinica Career Development Award, Academia Sinica, AS-CDA-109-L08 Infectious Disease Research Supporting Grant, AS-IDR-110-08.
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Affiliation(s)
- Mei-Hui Hou
- Genomics BioSci. & Tech. Co. Ltd., New Taipei, 221411, Taiwan
| | - Yu-Chuan Wang
- Genomics BioSci. & Tech. Co. Ltd., New Taipei, 221411, Taiwan
| | - Chia-Shin Yang
- Genomics BioSci. & Tech. Co. Ltd., New Taipei, 221411, Taiwan
| | - Kuei-Fen Liao
- National Synchrotron Radiation Research Center, Hsinchu Science Park, Hsinchu, 300092, Taiwan
| | - Je-Wei Chang
- National Synchrotron Radiation Research Center, Hsinchu Science Park, Hsinchu, 300092, Taiwan
| | - Orion Shih
- National Synchrotron Radiation Research Center, Hsinchu Science Park, Hsinchu, 300092, Taiwan
| | - Yi-Qi Yeh
- National Synchrotron Radiation Research Center, Hsinchu Science Park, Hsinchu, 300092, Taiwan
| | | | - Tzu-Wen Weng
- Institute of Biological Chemistry, Academia Sinica, Taipei, 115024, Taiwan
- Institute of Biochemical Sciences, National Taiwan University, Taipei, 106319, Taiwan
| | - U-Ser Jeng
- National Synchrotron Radiation Research Center, Hsinchu Science Park, Hsinchu, 300092, Taiwan
- Department of Chemical Engineering & College of Semiconductor Research, National Tsing Hua University, Hsinchu, 300044, Taiwan
| | - Shang-Te Danny Hsu
- Institute of Biological Chemistry, Academia Sinica, Taipei, 115024, Taiwan
- Institute of Biochemical Sciences, National Taiwan University, Taipei, 106319, Taiwan
| | - Yeh Chen
- Department of Food Science and Biotechnology, National Chung Hsing University, Taichung, 402202, Taiwan.
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Lin HH, Yu M, Sriramoju MK, Hsu STD, Liu CT, Lai EM. A High-Throughput Interbacterial Competition Screen Identifies ClpAP in Enhancing Recipient Susceptibility to Type VI Secretion System-Mediated Attack by Agrobacterium tumefaciens. Front Microbiol 2020; 10:3077. [PMID: 32117077 PMCID: PMC7012810 DOI: 10.3389/fmicb.2019.03077] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [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: 10/07/2019] [Accepted: 12/19/2019] [Indexed: 12/30/2022] Open
Abstract
The type VI secretion system (T6SS) is an effector delivery system used by Gram-negative bacteria to kill other bacteria or eukaryotic hosts to gain fitness. The plant pathogen Agrobacterium tumefaciens utilizes its T6SS to kill other bacteria, such as Escherichia coli. We observed that the A. tumefaciens T6SS-dependent killing outcome differs when using different T6SS-lacking, K-12 E. coli strains as a recipient cell. Thus, we hypothesized that the A. tumefaciens T6SS killing outcome not only relies on the T6SS activity of the attacker cells but also depends on the recipient cells. Here, we developed a high-throughput interbacterial competition platform to test the hypothesis by screening for mutants with reduced killing outcomes caused by A. tumefaciens strain C58. Among the 3,909 strains in the E. coli Keio library screened, 16 mutants with less susceptibility to A. tumefaciens C58 T6SS-dependent killing were identified, and four of them were validated by complementation test. Among the four, the clpP encoding ClpP protease, which is universal and highly conserved in both prokaryotes and eukaryotic organelles, was selected for further characterizations. We demonstrated that ClpP is responsible for enhancing susceptibility to the T6SS killing. Because ClpP protease depends on other adapter proteins such as ClpA and ClpX for substrate recognition, further mutant studies followed by complementation tests were carried out to reveal that ClpP-associated AAA+ ATPase ClpA, but not ClpX, is involved in enhancing susceptibility to A. tumefaciens T6SS killing. Moreover, functional and biochemical studies of various ClpP amino acid substitution variants provided evidence that ClpA–ClpP interaction is critical in enhancing susceptibility to the T6SS killing. This study highlights the importance of recipient factors in determining the outcome of the T6SS killing and shows the universal ClpP protease as a novel recipient factor hijacked by the T6SS of A. tumefaciens.
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Affiliation(s)
- Hsiao-Han Lin
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan.,Institute of Biotechnology, National Taiwan University, Taipei, Taiwan
| | - Manda Yu
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | | | | | - Chi-Te Liu
- Institute of Biotechnology, National Taiwan University, Taipei, Taiwan.,Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
| | - Erh-Min Lai
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
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Sriramoju MK, Chen Y, Hsu STD. Protein knots provide mechano-resilience to an AAA+ protease-mediated proteolysis with profound ATP energy expenses. Biochim Biophys Acta Proteins Proteom 2019; 1868:140330. [PMID: 31756432 DOI: 10.1016/j.bbapap.2019.140330] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Revised: 10/23/2019] [Accepted: 11/15/2019] [Indexed: 12/11/2022]
Abstract
Knotted proteins are some of the most fascinating examples of how linear polypeptide chains can achieve intricate topological arrangements efficiently and spontaneously. The entanglements of polypeptide chains could potentially enhance their folding stabilities. We recently reported the unprecedented mechanostability of the Gordian (52) knotted family of human ubiquitin C-terminal hydrolases (UCHs) in the context of withstanding the mechanical unfolding of the bacterial AAA+ proteasome, ClpXP; a green fluorescence protein (GFP) was fused to the N-terminus of various UCHs as a reporter of the unfolding and degradation of these topologically knotted substrates, but it also limited the ability to examine the effect of untying the knotted topology via N-terminal truncation. In this study, we directly monitored the ClpXP-mediated degradation of UCH variants by electrophoresis and quantitative imaging analyses. We demonstrated that untying of the 52 knot in UCHL1 via N-terminal truncation (UCHL1Δ11) significantly reduces its mechanostability. We further quantified the ATP expenditures of degrading different UCH variants by ClpXP. The unknotted UCHL1Δ11 underwent accelerated ClpXP-dependent proteolysis, with a 30-fold reduction in ATP consumption compared to the knotted wild type. Unlike all other known ClpXP substrates, UCHL5, which is the most resilient substrate known to date, significantly slowed down the ATP turnover rate by ClpXP. Furthermore, UCHL5 required 1000-fold more ATP to be fully degraded by ClpXP compared to GFP. Our results underscored how the complex, knotted folding topology in UCHs may interfere with the mechano-unfolding processes of the AAA+ unfoldase, ClpX.
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Affiliation(s)
| | - Yen Chen
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Shang-Te Danny Hsu
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan; Institute of Biochemical Sciences, National Taiwan University, Taipei 106, Taiwan.
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Sriramoju MK, Chen Y, Lee YTC, Hsu STD. Topologically knotted deubiquitinases exhibit unprecedented mechanostability to withstand the proteolysis by an AAA+ protease. Sci Rep 2018; 8:7076. [PMID: 29728659 PMCID: PMC5935755 DOI: 10.1038/s41598-018-25470-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 04/23/2018] [Indexed: 01/03/2023] Open
Abstract
More than one thousand knotted protein structures have been identified so far, but the functional roles of these knots remain elusive. It has been postulated that backbone entanglement may provide additional mechanostability. Here, we employed a bacterial proteasome, ClpXP, to mechanically unfold 52-knotted human ubiquitin C-terminal hydrolase (UCH) paralogs from their C-termini, followed by processive translocation into the proteolytic chamber for degradation. Our results revealed unprecedentedly slow kinetics of ClpXP-mediated proteolysis for the proteasome-associated UCHL5: ten thousand times slower than that of a green fluorescence protein (GFP), which has a comparable size to the UCH domain but much higher chemical and thermal stabilities. The ClpXP-dependent mechanostability positively correlates with the intrinsic unfolding rates of the substrates, spanning over several orders of magnitude for the UCHs. The broad range of mechanostability within the same protein family may be associated with the functional requirements for their differential malleabilities.
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Affiliation(s)
| | - Yen Chen
- Institute of Biological Chemistry, Academia Sinica, Taipei, 11529, Taiwan
| | - Yun-Tzai Cloud Lee
- Institute of Biological Chemistry, Academia Sinica, Taipei, 11529, Taiwan.,Institute of Biochemical Sciences, National Taiwan University, Taipei, 106, Taiwan
| | - Shang-Te Danny Hsu
- Institute of Biological Chemistry, Academia Sinica, Taipei, 11529, Taiwan. .,Institute of Biochemical Sciences, National Taiwan University, Taipei, 106, Taiwan.
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