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Han X, Hu Z, Surya W, Ma Q, Zhou F, Nordenskiöld L, Torres J, Lu L, Miao Y. The intrinsically disordered region of coronins fine-tunes oligomerization and actin polymerization. Cell Rep 2023; 42:112594. [PMID: 37269287 DOI: 10.1016/j.celrep.2023.112594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 04/21/2023] [Accepted: 05/16/2023] [Indexed: 06/05/2023] Open
Abstract
Coronins play critical roles in actin network formation. The diverse functions of coronins are regulated by the structured N-terminal β propeller and the C-terminal coiled coil (CC). However, less is known about a middle "unique region" (UR), which is an intrinsically disordered region (IDR). The UR/IDR is an evolutionarily conserved signature in the coronin family. By integrating biochemical and cell biology experiments, coarse-grained simulations, and protein engineering, we find that the IDR optimizes the biochemical activities of coronins in vivo and in vitro. The budding yeast coronin IDR plays essential roles in regulating Crn1 activity by fine-tuning CC oligomerization and maintaining Crn1 as a tetramer. The IDR-guided optimization of Crn1 oligomerization is critical for F-actin cross-linking and regulation of Arp2/3-mediated actin polymerization. The final oligomerization status and homogeneity of Crn1 are contributed by three examined factors: helix packing, the energy landscape of the CC, and the length and molecular grammar of the IDR.
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Affiliation(s)
- Xiao Han
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Zixin Hu
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Wahyu Surya
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Qianqian Ma
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Feng Zhou
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Lars Nordenskiöld
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Jaume Torres
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Lanyuan Lu
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Yansong Miao
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore; Institute for Digital Molecular Analytics and Science, Nanyang Technological University, Singapore 636921, Singapore.
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2
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Structural basis of rapid actin dynamics in the evolutionarily divergent Leishmania parasite. Nat Commun 2022; 13:3442. [PMID: 35705539 PMCID: PMC9200798 DOI: 10.1038/s41467-022-31068-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 06/01/2022] [Indexed: 11/08/2022] Open
Abstract
Actin polymerization generates forces for cellular processes throughout the eukaryotic kingdom, but our understanding of the ‘ancient’ actin turnover machineries is limited. We show that, despite > 1 billion years of evolution, pathogenic Leishmania major parasite and mammalian actins share the same overall fold and co-polymerize with each other. Interestingly, Leishmania harbors a simple actin-regulatory machinery that lacks cofilin ‘cofactors’, which accelerate filament disassembly in higher eukaryotes. By applying single-filament biochemistry we discovered that, compared to mammalian proteins, Leishmania actin filaments depolymerize more rapidly from both ends, and are severed > 100-fold more efficiently by cofilin. Our high-resolution cryo-EM structures of Leishmania ADP-, ADP-Pi- and cofilin-actin filaments identify specific features at actin subunit interfaces and cofilin-actin interactions that explain the unusually rapid dynamics of parasite actin filaments. Our findings reveal how divergent parasites achieve rapid actin dynamics using a remarkably simple set of actin-binding proteins, and elucidate evolution of the actin cytoskeleton. The authors report here the structure-function analysis of highly divergent actin from Leishmania parasite. The study reveals remarkably rapid dynamics of parasite actin as well as the underlying molecular basis, thus providing insight into evolution of the actin cytoskeleton.
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Parihar PS, Singh A, Karade SS, Sahasrabuddhe AA, Pratap JV. Structural insights into kinetoplastid coronin oligomerization domain and F-actin interaction. Curr Res Struct Biol 2021; 3:268-276. [PMID: 34746809 PMCID: PMC8554105 DOI: 10.1016/j.crstbi.2021.10.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 09/18/2021] [Accepted: 10/11/2021] [Indexed: 12/25/2022] Open
Abstract
The two-domain actin associated protein coronin interacts with filamentous (F-) actin, facilitating diverse biological processes including cell proliferation, motility, phagocytosis, host-parasite interaction and cargo binding. The conserved N-terminal β-propeller domain is involved in protein: protein interactions, while the C-terminal coiled-coil domain mediates oligomerization, transducing conformational changes. The L. donovani coronin coiled-coil (LdCoroCC) domain exhibited a novel topology and oligomer association with an inherent asymmetry, caused primarily by three a residues of successive heptads. In the T.brucei homolog (TbrCoro), two of these 'a' residues are different (Val 493 & 507 replacing LdCoroCC Ile 486 and Met 500 respectively). The elucidated structure possesses a similar topology and assembly while comparative structural analysis shows that the T.brucei coronin coiled-coil domain (TbrCoroCC) too possesses the asymmetry though its magnitude is smaller. Analysis identifies that the asymmetric state is stabilized via cyclic salt bridges formed by Arg 497 and Glu 504. Co-localization studies (LdCoro, TbrCoro and corresponding mutant coiled coil constructs) with actin show that there are subtle differences in their binding patterns, with the double mutant V493I-V507M showing maximal effect. None of the constructs have an effect on F-actin length. Taken together with LdCoroCC, we therefore conclude that the inherent asymmetric structures are essential for kinetoplastids, and are of interest in understanding and exploiting actin dynamics.
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Affiliation(s)
- Pankaj Singh Parihar
- Division of Biochemistry and Structural Biology, CSIR - Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, 226031, Uttar Pradesh, India
| | - Aastha Singh
- Division of Biochemistry and Structural Biology, CSIR - Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, 226031, Uttar Pradesh, India
| | - Sharanbasappa Shrimant Karade
- Division of Biochemistry and Structural Biology, CSIR - Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, 226031, Uttar Pradesh, India
| | - Amogh Anant Sahasrabuddhe
- Division of Biochemistry and Structural Biology, CSIR - Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, 226031, Uttar Pradesh, India
| | - J Venkatesh Pratap
- Division of Biochemistry and Structural Biology, CSIR - Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, 226031, Uttar Pradesh, India
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4
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Gupta CM, Ambaru B, Bajaj R. Emerging Functions of Actins and Actin Binding Proteins in Trypanosomatids. Front Cell Dev Biol 2020; 8:587685. [PMID: 33163497 PMCID: PMC7581878 DOI: 10.3389/fcell.2020.587685] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 09/22/2020] [Indexed: 01/20/2023] Open
Abstract
Actin is the major protein constituent of the cytoskeleton that performs wide range of cellular functions. It exists in monomeric and filamentous forms, dynamics of which is regulated by a large repertoire of actin binding proteins. However, not much was known about existence of these proteins in trypanosomatids, till the genome sequence data of three important organisms of this class, viz. Trypanosoma brucei, Trypanosoma cruzi and Leishmania major, became available. Here, we have reviewed most of the findings reported to date on the intracellular distribution, structure and functions of these proteins and based on them, we have hypothesized some of their functions. The major findings are as follows: (1) All the three organisms encode at least a set of ten actin binding proteins (profilin, twinfilin, ADF/cofilin, CAP/srv2, CAPz, coronin, two myosins, two formins) and one isoform of actin, except that T. cruzi encodes for three formins and several myosins along with four actins. (2) Actin 1 and a few actin binding proteins (ADF/cofilin, profilin, twinfilin, coronin and myosin13 in L. donovani; ADF/cofilin, profilin and myosin1 in T. brucei; profilin and myosin-F in T.cruzi) have been identified and characterized. (3) In all the three organisms, actin cytoskeleton has been shown to regulate endocytosis and intracellular trafficking. (4) Leishmania actin1 has been the most characterized protein among trypanosomatid actins. (5) This protein is localized to the cytoplasm as well as in the flagellum, nucleus and kinetoplast, and in vitro, it binds to DNA and displays scDNA relaxing and kDNA nicking activities. (6) The pure protein prefers to form bundles instead of thin filaments, and does not bind DNase1 or phalloidin. (7) Myosin13, myosin1 and myosin-F regulate endocytosis and intracellular trafficking, respectively, in Leishmania, T. brucei and T. cruzi. (8) Actin-dependent myosin13 motor is involved in dynamics and assembly of Leishmania flagellum. (9) Leishmania twinfilin localizes mostly to the nucleolus and coordinates karyokinesis by effecting splindle elongation and DNA synthesis. (10) Leishmania coronin binds and promotes actin filament formation and exists in tetrameric form rather than trimeric form, like other coronins. (11) Trypanosomatid profilins are essential for survival of all the three parasites.
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Affiliation(s)
- Chhitar M Gupta
- Institute of Bioinformatics and Applied Biotechnology, Bengaluru, India
| | - Bindu Ambaru
- Institute of Bioinformatics and Applied Biotechnology, Bengaluru, India.,Manipal Academy of Higher Education, Manipal, India
| | - Rani Bajaj
- Institute of Bioinformatics and Applied Biotechnology, Bengaluru, India.,Manipal Academy of Higher Education, Manipal, India
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5
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Chen Y, Xu J, Zhang Y, Ma S, Yi W, Liu S, Yu X, Wang J, Chen Y. Coronin 2B regulates dendrite outgrowth by modulating actin dynamics. FEBS Lett 2020; 594:2975-2987. [PMID: 32692409 DOI: 10.1002/1873-3468.13886] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/13/2020] [Accepted: 07/06/2020] [Indexed: 01/31/2023]
Abstract
Cytoskeletal remodeling is indispensable for the development and maintenance of neuronal structures and functions. However, the molecular machinery that controls the balance between actin polymerization and depolymerization during these processes is incompletely understood. Here, we report that coronin 2B, a conserved actin-binding protein, is concentrated at the tips of developing dendrites and that knockdown of coronin 2B inhibits the growth of dendrites. Importantly, coronin 2B interacts with actin and reduces the F-actin/G-actin ratio. Furthermore, the coiled-coil domain of coronin 2B is required for its oligomerization, thus confining coronin 2B to neurite tips. Our findings collectively suggest that coronin 2B is important for promoting dendrite outgrowth by limiting the speed of actin polymerization at growth cones.
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Affiliation(s)
- Yuewen Chen
- The Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science - Shenzhen Fundamental Research Institutions, Shenzhen, China.,University of Chinese Academy of Sciences, Beijing, China.,Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, Shenzhen-Hong Kong Institute of Brain Science, HKUST Shenzhen Research Institute, Shenzhen, China
| | - Jinying Xu
- The Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science - Shenzhen Fundamental Research Institutions, Shenzhen, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yulin Zhang
- Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, Shenzhen-Hong Kong Institute of Brain Science, HKUST Shenzhen Research Institute, Shenzhen, China
| | - Shuangshuang Ma
- Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, Shenzhen-Hong Kong Institute of Brain Science, HKUST Shenzhen Research Institute, Shenzhen, China
| | - Wanying Yi
- Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, Shenzhen-Hong Kong Institute of Brain Science, HKUST Shenzhen Research Institute, Shenzhen, China
| | - Saijuan Liu
- Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, Shenzhen-Hong Kong Institute of Brain Science, HKUST Shenzhen Research Institute, Shenzhen, China
| | - Xiaojun Yu
- Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, Shenzhen-Hong Kong Institute of Brain Science, HKUST Shenzhen Research Institute, Shenzhen, China
| | - Jiali Wang
- Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, Shenzhen-Hong Kong Institute of Brain Science, HKUST Shenzhen Research Institute, Shenzhen, China
| | - Yu Chen
- The Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science - Shenzhen Fundamental Research Institutions, Shenzhen, China.,University of Chinese Academy of Sciences, Beijing, China.,Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, Shenzhen-Hong Kong Institute of Brain Science, HKUST Shenzhen Research Institute, Shenzhen, China
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6
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Fiedler T, Fabrice TN, Studer V, Vinet A, Faltova L, Kammerer RA, Steinmetz MO, Sharpe T, Pieters J. Homodimerization of coronin A through the C-terminal coiled-coil domain is essential for multicellular differentiation of Dictyostelium discoideum. FEBS Lett 2020; 594:2116-2127. [PMID: 32298460 DOI: 10.1002/1873-3468.13787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 03/25/2020] [Accepted: 03/26/2020] [Indexed: 11/09/2022]
Abstract
Coronin proteins are widely expressed among eukaryotic organisms. Most coronins consist of a WD-repeat domain followed by a C-terminal coiled coil. Dictyostelium discoideum expresses a single short coronin coronin A, which has been implicated in both actin modulation and multicellular differentiation. Whether coronin A's coiled coil is important for functionality, as well as the oligomeric state of coronin A is not known. Here, we show that the coiled-coil domain in Dictyostelium coronin A functions in homodimerization, is dispensable for coronin A stability and localization but essential for multicellular differentiation. These results allow a better understanding of the role for the coiled-coil domain of coronin A in oligomerization and demonstrate that its presence is essential for multicellular differentiation.
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Affiliation(s)
| | | | - Vera Studer
- Biozentrum, University of Basel, Switzerland
| | | | - Lenka Faltova
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, Villigen, Switzerland
| | - Richard A Kammerer
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, Villigen, Switzerland
| | - Michel O Steinmetz
- Biozentrum, University of Basel, Switzerland
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, Villigen, Switzerland
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7
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Karade SS, Ansari A, Srivastava VK, Nayak AR, Pratap JV. Molecular and structural analysis of a mechanical transition of helices in the L. donovani coronin coiled-coil domain. Int J Biol Macromol 2020; 143:785-796. [PMID: 31778699 DOI: 10.1016/j.ijbiomac.2019.09.138] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 09/04/2019] [Accepted: 09/18/2019] [Indexed: 11/30/2022]
Abstract
Protein-protein interactions of cellular importance are mediated by coiled coils (CCs), the ubiquitous structural motif formed by the association of two or more α-helices in a knobs into holes manner. Coronins, actin-associated multi-functional proteins that possess distinct cytoskeleton-dependent and independent functions, oligomerize through their C-terminal CC domain. The structure of the L. donovani coronin CC domain (LdCoroCC; PDB ID 5CX2) revealed, in addition to a novel topology and architecture, an inherent asymmetry, with one of the helices of the 4-helix bundle axially shifted (~2 turns). The structural analysis identified that steric hindrance by Ile 486, Leu 493 and Met 500 as the cause for this asymmetry. To experimentally validate this hypothesis and to better understand the sequence-structure relationship in CCs, these amino acids have been mutated (I486A, L493A, M500V and the double mutant I486A-L493A) and characterized. Thermal CD studies suggest that the I486A and M500V mutants have comparable Tm values to LdCoroCC, while the other mutants have lower melting temperatures. The mutant crystal structures (I486A, M500V and the double mutant) retain the 'ade' core packing as LdcoroCC. While the M500V structure is similar to LdCoroCC, the I486A and the I486A-L493A structures show an asymmetry to symmetry transition. This study reveals crucial role of residues at position 'a' in coiled-coil domain play an important role in stabilizing the asymmetry in LdCoroCC, which might be necessary pursue specific biological function(s) inside the Leishmania.
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Affiliation(s)
- Sharanbasappa Shrimant Karade
- Molecular and Structural Biology Division, CSIR - Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, Uttar Pradesh, India
| | - Ahmadullah Ansari
- Molecular and Structural Biology Division, CSIR - Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, Uttar Pradesh, India
| | - Vijay Kumar Srivastava
- Molecular and Structural Biology Division, CSIR - Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, Uttar Pradesh, India
| | - Ashok Ranjan Nayak
- Molecular and Structural Biology Division, CSIR - Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, Uttar Pradesh, India
| | - J Venkatesh Pratap
- Molecular and Structural Biology Division, CSIR - Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, Uttar Pradesh, India.
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8
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Moreira A, Figueira E, Mestre NC, Schrama D, Soares AMVM, Freitas R, Bebianno MJ. Impacts of the combined exposure to seawater acidification and arsenic on the proteome of Crassostrea angulata and Crassostrea gigas. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2018; 203:117-129. [PMID: 30119036 DOI: 10.1016/j.aquatox.2018.07.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 07/25/2018] [Accepted: 07/28/2018] [Indexed: 06/08/2023]
Abstract
Proteomic analysis was performed to compare the effects of Arsenic (As), seawater acidification (Low pH) and the combination of both stressors (Low pH + As) on Crassostrea angulata and Crassostrea gigas juveniles in the context of global environmental change. This study aimed to elucidate if two closely related Crassostrea species respond similarly to these environmental stressors, considering both single and combined exposures, to infer if the simultaneous exposure to both stressors induced a differentiated response. Identification of the most important differentially expressed proteins between conditions revealed marked differences in the response of each species towards single and combined exposures, evidencing species-related differences towards each experimental condition. Moreover, protein alterations observed in the combined exposure (Low pH + As) were substantially different from those observed in single exposures. Identified proteins and their putative biological functions revealed an array of modes of action in each condition. Among the most important, those involved in cellular structure (Actin, Atlastin, Severin, Gelsolin, Coronin) and extracellular matrix modulation (Ependymin, Tight junction ZO-1, Neprilysin) were strongly regulated, although in different exposure conditions and species. Data also revealed differences regarding metabolic modulation capacity (ATP β, Enolase, Aconitate hydratase) and oxidative stress response (Aldehyde dehydrogenase, Lactoylglutathione, Retinal dehydrogenase) of each species, which also depended on single or combined exposures, illustrating a different response capacity of both oyster species to the presence of multiple stressors. Interestingly, alterations of piRNA abundance in C. angulata suggested genome reconfiguration in response to multiple stressors, likely an important mode of action related to adaptive evolution mechanisms previously unknown to oyster species, which requires further investigation. The present findings provide a deeper insight into the complexity of C. angulata and C. gigas responses to environmental stress at the proteome level, evidencing different capacities to endure abiotic changes, with relevance regarding the ecophysiological fitness of each species and competitive advantages in a changing environment.
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Affiliation(s)
- Anthony Moreira
- Departamento de Biologia & CESAM, Universidade de Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
| | - Etelvina Figueira
- Departamento de Biologia & CESAM, Universidade de Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
| | - Nélia C Mestre
- CIMA, Universidade do Algarve, Campus de Gambelas, Faro, Portugal
| | - Denise Schrama
- CCMAR, Universidade do Algarve, Campus de Gambelas, Faro, Portugal
| | - Amadeu M V M Soares
- Departamento de Biologia & CESAM, Universidade de Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
| | - Rosa Freitas
- Departamento de Biologia & CESAM, Universidade de Aveiro, Campus Universitário de Santiago, Aveiro, Portugal.
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9
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Nayak AR, Karade SS, Srivastava VK, Rana AK, Gupta CM, Sahasrabuddhe AA, Pratap JV. Structure of Leishmania donovani coronin coiled coil domain reveals an antiparallel 4 helix bundle with inherent asymmetry. J Struct Biol 2016; 195:129-38. [PMID: 26940672 DOI: 10.1016/j.jsb.2016.02.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 02/26/2016] [Accepted: 02/27/2016] [Indexed: 11/26/2022]
Abstract
Coiled coils are ubiquitous structural motifs that serve as a platform for protein-protein interactions and play a central role in myriad physiological processes. Though the formation of a coiled coil requires only the presence of suitably spaced hydrophobic residues, sequence specificities have also been associated with specific oligomeric states. RhXXhE is one such sequence motif, associated with parallel trimers, found in coronins and other proteins. Coronin, present in all eukaryotes, is an actin-associated protein involved in regulating actin turnover. Most eukaryotic coronins possess the RhXXhE trimerization motif. However, a unique feature of parasitic kinetoplastid coronin is that the positions of R and E are swapped within their coiled coil domain, but were still expected to form trimers. To understand the role of swapped motif in oligomeric specificity, we determined the X-ray crystal structure of Leishmania donovani coronin coiled coil domain (LdCoroCC) at 2.2Å, which surprisingly, reveals an anti-parallel tetramer assembly. Small angle X-ray scattering studies and chemical crosslinking confirm the tetramer in solution and is consistent with the oligomerization observed in the full length protein. Structural analyses reveal that LdCoroCC possesses an inherent asymmetry, in that one of the helices of the bundle is axially shifted with respect to the other three. The analysis also identifies steric reasons that cause this asymmetry. The bundle adapts an extended a-d-e core packing, the e residue being polar (with an exception) which results in a thermostable bundle with polar and apolar interfaces, unlike the existing a-d-e core antiparallel homotetramers with apolar core. Functional implications of the anti-parallel association in kinetoplastids are discussed.
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Affiliation(s)
- Ashok Ranjan Nayak
- Division of Molecular and Structural Biology, CSIR - Central Drug Research Institute, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Sharanbasappa Shrimant Karade
- Division of Molecular and Structural Biology, CSIR - Central Drug Research Institute, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Vijay Kumar Srivastava
- Division of Molecular and Structural Biology, CSIR - Central Drug Research Institute, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Ajay Kumar Rana
- Division of Molecular and Structural Biology, CSIR - Central Drug Research Institute, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - C M Gupta
- Division of Molecular and Structural Biology, CSIR - Central Drug Research Institute, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Amogh A Sahasrabuddhe
- Division of Molecular and Structural Biology, CSIR - Central Drug Research Institute, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - J Venkatesh Pratap
- Division of Molecular and Structural Biology, CSIR - Central Drug Research Institute, Jankipuram Extension, Sitapur Road, Lucknow 226031, India.
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