Structure of the Plant Plastid-Encoded RNA Polymerase
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Q Exactive HF-X
ORGANISM(S): Sinapis Alba
TISSUE(S): Plant Cell, Photosynthetic Cell, Leaf, Shoot
SUBMITTER: 
Jason Low
LAB HEAD: Michael Webster
PROVIDER: PXD045575 | Pride | 2024-03-01
REPOSITORIES: Pride
Similar Datasets
Project description:The tumor suppressor protein p53 is a transcription factor that is referred to as the “guardian of the genome” and plays an important role in cancer development. P53 is active as a tetramer; the S100β homodimer binds to the intrinsically disordered C-terminus of p53, affecting its transcriptional activity. The p53/S100β complex is regarded as highly promising therapeutic target in cancer. It has been suggested that S100β exerts its oncogenic effects by altering the p53 oligomeric state. Our aim was to study the structures and oligomerization behavior of different p53/S100β complexes by electrospray ionization mass spectrometry (ESI-MS), cross-linking mass spectrometry (XL-MS), and surface plasmon resonance (SPR). For this, wild-type p53 and single amino acid variants, representing different oligomeric states of p53 (tetrameric wild-type, dimeric L344A variant, and monomeric L344P variant) were individually investigated regarding their binding behavior towards S100β. The stoichiometry of the different p53/S100β complexes were determined by ESI-MS showing that tetrameric, dimeric, and monomeric p53 variants all bind to an S100β dimer. In addition, XL-MS revealed the topologies of the p53/S100β complexes to be independent of p53’s oligomeric state. With SPR, the thermodynamic parameters were determined for S100β binding to tetrameric, dimeric or monomeric p53 variants. Our data prove that the S100β homodimer binds to different oligomeric states of p53 with identical stoichiometries and similar binding affinities. This emphasizes the need for alternative explanations to describe the molecular mechanisms underlying p53/S100β interaction.
2022-10-14 | PXD029914 | Pride
Project description:This data is from sulfo-SDA crosslinked condensin pentamer. Two datsets, one without atp aand one with ATP. How protein complexes of the SMC family fold DNA into the large loops that are fundamental for the 3D organization of genomes is a central unresolved question of chromosome biology. We used electron cryomicroscopy to investigate the reaction cycle of the SMC complex condensin, which is a key determinant of chromosome morphology and behavior during mitosis. Our structures of the Saccharomyces cerevisiae condensin holo complex at different functional stages suggest that ATP binding induces the transition from a folded-rod SMC conformation into an open architecture and triggers the exchange of the two HEAT-repeat subunits at the SMC ATPase head domains. We propose that these steps result in the interconversion of DNA binding sites in the catalytic core that form the basis of the DNA translocation and loop-extrusion activities of condensin.
2020-07-28 | PXD019274 | Pride
Project description:The tricarboxylic acid (TCA) cycle, or Krebs cycle, is the central pathway of energy production in eukaryotic cells and plays a key part in aerobic respiration throughout all kingdoms of life. The enzymes involved in this cycle generate the reducing equivalents NADH and FADH2 by a series of enzymatic reactions, which are utilized by the electron transport chain to produce ATP. One of the key enzymes in this cycle is 2-oxoglutarate dehydrogenase (OGDHC), which generates NADH by oxidative decarboxylation of 2-oxoglutarate to succinyl-CoA. Notably, this enzyme consists of multiple subunits as a megadalton protein complex. Thus far, it was thought that OGDHC consists of solely three catalytically active subunits (E1, E2, E3). However in fungi and animals, the small protein MRPS36 has been proposed as a putative additional component. Based on extensive XL-MS data obtained from measurements in both, mice and bovine heart mitochondria, and from phylogenetic analyses, we provide structural evidence that MRPS36 is an exclusive and crucial member of eukaryotic OGDHC. Comparative genomics analysis and computational structure predictions reveal that in eukaryotic OGDHC, E2o does not contain a peripheral subunit-binding (PSBD) domain. Instead, our data provide compelling evidence that in eukaryotes, MRPS36 evolved as E3 adaptor protein, functionally replacing the PSBD domain. Based on our data we provide a refined structural model of the complete eukaryotic OGDHC assembly containing all its 58 subunits (~ 3.4 MDa). The model provides new insights into the protein-protein interactions within the OGDH complex and highlights putative mechanistic implications.
2023-03-10 | PXD036896 | Pride
Project description:Combining mass spectrometry based chemical cross-linking and complexome profiling, we analyzed the interactome of heart mitochondria. We focused on complexes of oxidative phosphorylation and found that dimeric apoptosis inducing factor 1 (AIFM1) forms a defined complex with ~10% of monomeric cytochrome c oxidase (COX), but hardly interacts with respiratory chain supercomplexes. Multiple AIFM1 inter-crosslinks engaging six different COX subunits provided structural restraints to build a detailed atomic model of the COX-AIFM12 complex. Application of two complementary proteomic approaches thus provided unexpected insight into the macromolecular organization of the mitochondrial complexome. Our structural model excludes direct electron transfer between AIFM1 and COX. Notably however, the binding site of cytochrome c remains accessible allowing formation of a ternary complex. The discovery of the previously overlooked COX-AIFM12 complex and clues provided by the structural model hint at a role of AIFM1 in OXPHOS biogenesis and in programmed cell death.
2021-09-09 | PXD025102 | Pride
Project description:Protein-protein interaction within the MGM holocomplex has been investigated by chemical cross-linking mass spectrometry using EDC (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide) cross-linker. Although this analysis was not exhaustive, we observed crosslinks between Alp4 and Alp6 along the length of these two proteins, consistent with their general parallel lateral alignment in current models for gamma-TuC organization. In addition, we observed specific cross-links from both Alp4 and Alp6 to the Mto1 [bonsai] CM1 domain and/or its immediate flanking regions. Interestingly, crosslinks from Alp4 and Alp6 N-terminal regions tended to be to the C-terminal portion of the CM1 domain, while crosslinks from Alp4 and Alp6 C-terminal regions tended to be to the N-terminal portion of the CM1 domain. This raises the possibility that the CM1 domain, which is adjacent to coiled-coil regions, may be oriented antiparallel to Alp4 and Alp6.
2019-05-27 | PXD012624 | Pride
Project description:Multiple studies to date have shown that high-density lipoprotein (HDL) levels are reduced in patients with coronavirus disease 2019 (COVID-19), and that the extent of this reduction is associated with poor clinical outcomes. While lipoproteins are known to play a key role during the lifecycle of hepatitis C virus, the direct influence they have upon coronavirus (CoV) infections remains poorly understood. In this study we utilise cross-linking mass spectrometry (XL-MS) to determine circulating protein interactors of the severe acute respiratory syndrome (SARS)-CoV-2 spike glycoprotein. Spike was revealed to interact with HDL, through direct interactions with apolipoprotein (Apo)-A1, ApoC3 and ApoD, highlighting multiple modalities of how SARS-CoV-2 and HDL may interact. XL-MS of plasma isolated from COVID-19 patients uncovered HDL protein interaction networks, dominated by acute phase serum amyloid proteins (SAA), whereby serum amyloid A2 (SAA2) was shown to bind to ApoD. ApoD was confirmed to also interact with core apolipoproteins of both LDL and VLDL, suggesting that SARS-CoV-2 may bind multiple lipoprotein species. The interaction between ApoD and spike was further validated in cells using immunoprecipitation-MS, which uncovered a novel interaction between both ApoD and spike with membrane-associated progesterone receptor component 1 (PGRMC1). Mechanistically, XL-MS coupled with data-driven structural modelling determined that ApoD may interact within the receptor-binding domain (RBD) of spike, posing the hypothesis that ApoD may interfere with binding to the angiotensin-converting enzyme 2 (ACE2) receptor. However, utilising multiple cell-based assays we determined ApoD to have no effect upon viral replication or infectivity.
2023-07-20 | PXD041438 | Pride
Project description:Multiple studies to date have shown that high-density lipoprotein (HDL) levels are reduced in patients with coronavirus disease 2019 (COVID-19), and that the extent of this reduction is associated with poor clinical outcomes. While lipoproteins are known to play a key role during the lifecycle of hepatitis C virus, the direct influence they have upon coronavirus (CoV) infections remains poorly understood. In this study we utilise cross-linking mass spectrometry (XL-MS) to determine circulating protein interactors of the severe acute respiratory syndrome (SARS)-CoV-2 spike glycoprotein. Spike was revealed to interact with HDL, through direct interactions with apolipoprotein (Apo)-A1, ApoC3 and ApoD, highlighting multiple modalities of how SARS-CoV-2 and HDL may interact. XL-MS of plasma isolated from COVID-19 patients uncovered HDL protein interaction networks, dominated by acute phase serum amyloid proteins (SAA), whereby serum amyloid A2 (SAA2) was shown to bind to ApoD. ApoD was confirmed to also interact with core apolipoproteins of both LDL and VLDL, suggesting that SARS-CoV-2 may bind multiple lipoprotein species. The interaction between ApoD and spike was further validated in cells using immunoprecipitation-MS, which uncovered a novel interaction between both ApoD and spike with membrane-associated progesterone receptor component 1 (PGRMC1). Mechanistically, XL-MS coupled with data-driven structural modelling determined that ApoD may interact within the receptor-binding domain (RBD) of spike, posing the hypothesis that ApoD may interfere with binding to the angiotensin-converting enzyme 2 (ACE2) receptor. However, utilising multiple cell-based assays we determined ApoD to have no effect upon viral replication or infectivity.
2023-07-20 | PXD042625 | Pride
Project description:Multiple studies to date have shown that high-density lipoprotein (HDL) levels are reduced in patients with coronavirus disease 2019 (COVID-19), and that the extent of this reduction is associated with poor clinical outcomes. While lipoproteins are known to play a key role during the lifecycle of hepatitis C virus, the direct influence they have upon coronavirus (CoV) infections remains poorly understood. In this study we utilise cross-linking mass spectrometry (XL-MS) to determine circulating protein interactors of the severe acute respiratory syndrome (SARS)-CoV-2 spike glycoprotein. Spike was revealed to interact with HDL, through direct interactions with apolipoprotein (Apo)-A1, ApoC3 and ApoD, highlighting multiple modalities of how SARS-CoV-2 and HDL may interact. XL-MS of plasma isolated from COVID-19 patients uncovered HDL protein interaction networks, dominated by acute phase serum amyloid proteins (SAA), whereby serum amyloid A2 (SAA2) was shown to bind to ApoD. ApoD was confirmed to also interact with core apolipoproteins of both LDL and VLDL, suggesting that SARS-CoV-2 may bind multiple lipoprotein species. The interaction between ApoD and spike was further validated in cells using immunoprecipitation-MS, which uncovered a novel interaction between both ApoD and spike with membrane-associated progesterone receptor component 1 (PGRMC1). Mechanistically, XL-MS coupled with data-driven structural modelling determined that ApoD may interact within the receptor-binding domain (RBD) of spike, posing the hypothesis that ApoD may interfere with binding to the angiotensin-converting enzyme 2 (ACE2) receptor. However, utilising multiple cell-based assays we determined ApoD to have no effect upon viral replication or infectivity.
2023-07-20 | PXD036640 | Pride
Project description:Multiple studies to date have shown that high-density lipoprotein (HDL) levels are reduced in patients with coronavirus disease 2019 (COVID-19), and that the extent of this reduction is associated with poor clinical outcomes. While lipoproteins are known to play a key role during the lifecycle of hepatitis C virus, the direct influence they have upon coronavirus (CoV) infections remains poorly understood. In this study we utilise cross-linking mass spectrometry (XL-MS) to determine circulating protein interactors of the severe acute respiratory syndrome (SARS)-CoV-2 spike glycoprotein. Spike was revealed to interact with HDL, through direct interactions with apolipoprotein (Apo)-A1, ApoC3 and ApoD, highlighting multiple modalities of how SARS-CoV-2 and HDL may interact. XL-MS of plasma isolated from COVID-19 patients uncovered HDL protein interaction networks, dominated by acute phase serum amyloid proteins (SAA), whereby serum amyloid A2 (SAA2) was shown to bind to ApoD. ApoD was confirmed to also interact with core apolipoproteins of both LDL and VLDL, suggesting that SARS-CoV-2 may bind multiple lipoprotein species. The interaction between ApoD and spike was further validated in cells using immunoprecipitation-MS, which uncovered a novel interaction between both ApoD and spike with membrane-associated progesterone receptor component 1 (PGRMC1). Mechanistically, XL-MS coupled with data-driven structural modelling determined that ApoD may interact within the receptor-binding domain (RBD) of spike, posing the hypothesis that ApoD may interfere with binding to the angiotensin-converting enzyme 2 (ACE2) receptor. However, utilising multiple cell-based assays we determined ApoD to have no effect upon viral replication or infectivity.
2023-07-20 | PXD041831 | Pride
Project description:We introduce a complimentary, heterobifunctional, photoactivatable, benzophenone containing cross-linker and show its successful application to cross-linking/mass spectrometry, by increasing data density, when used alongside a previously developed diazirine-based heterobifunctional cross-linker.
2017-04-26 | PXD004920 | Pride