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Open data
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Basic information
| Entry | ![]() | |||||||||
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| Title | Structure of the GH13 domain of Ruminococcus bromii Amy4 | |||||||||
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Sample |
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Keywords | GH13 / Ruminococcus bromii / Amy4 / HYDROLASE | |||||||||
| Biological species | Ruminococcus bromii L2-63 (bacteria) | |||||||||
| Method | single particle reconstruction / cryo EM / Resolution: 2.8 Å | |||||||||
Authors | Wimmer BH / Medalia O | |||||||||
| Funding support | Switzerland, 1 items
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Citation | Journal: Nat Commun / Year: 2025Title: Spatial constraints drive amylosome-mediated resistant starch degradation by Ruminococcus bromii in the human colon. Authors: Benedikt H Wimmer / Sarah Moraïs / Itai Amit / Omar Tovar-Herrera / Meltem Tatli / Anke Trautwein-Schult / Barbara Pfister / Ran Zalk / Paloma Tödtli / Sebastian Simoni / Matteo Lisibach / ...Authors: Benedikt H Wimmer / Sarah Moraïs / Itai Amit / Omar Tovar-Herrera / Meltem Tatli / Anke Trautwein-Schult / Barbara Pfister / Ran Zalk / Paloma Tödtli / Sebastian Simoni / Matteo Lisibach / Liron Levin / Dörte Becher / Edward A Bayer / Ohad Medalia / Itzhak Mizrahi / ![]() Abstract: Degradation of complex dietary fiber by gut microbes is essential for colonic fermentation, short-chain fatty acid production, and microbiome function. Ruminococcus bromii is the primary resistant ...Degradation of complex dietary fiber by gut microbes is essential for colonic fermentation, short-chain fatty acid production, and microbiome function. Ruminococcus bromii is the primary resistant starch (RS) degrader in humans, which relies on the amylosome, a specialized cell-bound enzymatic complex. To unravel its architecture, function, and the interplay among its components, we applied a holistic multilayered approach: Cryo-electron tomography reveals that the amylosome comprises a constitutive extracellular layer extending toward the RS substrate. Proteomics demonstrates remodeling of its contents across different growth conditions, with Amy4 and Amy16 comprising 60% of the amylosome in response to RS. Structural and biochemical analyses reveal complementarity and synergistic RS degradation by these enzymes. We demonstrate that amylosome composition and RS degradation are regulated at two levels: structural constraints and expression-driven shifts in enzyme proportions enforce enzyme proximity, which allows R. bromii to fine-tune its adaptation to dietary fiber and shape colonic metabolism. | |||||||||
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Structure visualization
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Downloads & links
-EMDB archive
| Map data | emd_53097.map.gz | 169.6 MB | EMDB map data format | |
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| Header (meta data) | emd-53097-v30.xml emd-53097.xml | 23 KB 23 KB | Display Display | EMDB header |
| FSC (resolution estimation) | emd_53097_fsc.xml | 12.8 KB | Display | FSC data file |
| Images | emd_53097.png | 33.2 KB | ||
| Masks | emd_53097_msk_1.map | 216 MB | Mask map | |
| Filedesc metadata | emd-53097.cif.gz | 7.3 KB | ||
| Others | emd_53097_half_map_1.map.gz emd_53097_half_map_2.map.gz | 200.5 MB 200.5 MB | ||
| Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-53097 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-53097 | HTTPS FTP |
-Related structure data
| Related structure data | ![]() 9qf3MC ![]() 9qf8C ![]() 9qf9C ![]() 9qfaC M: atomic model generated by this map C: citing same article ( |
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Links
| EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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Map
| File | Download / File: emd_53097.map.gz / Format: CCP4 / Size: 216 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||
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| Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||
| Voxel size | X=Y=Z: 0.651 Å | ||||||||||||||||||||||||||||||||||||
| Density |
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| Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||
| Details | EMDB XML:
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-Supplemental data
-Mask #1
| File | emd_53097_msk_1.map | ||||||||||||
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-Half map: #1
| File | emd_53097_half_map_1.map | ||||||||||||
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-Half map: #2
| File | emd_53097_half_map_2.map | ||||||||||||
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Sample components
-Entire : Ruminococcus bromii Amy4
| Entire | Name: Ruminococcus bromii Amy4 |
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| Components |
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-Supramolecule #1: Ruminococcus bromii Amy4
| Supramolecule | Name: Ruminococcus bromii Amy4 / type: complex / ID: 1 / Parent: 0 / Macromolecule list: all |
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| Source (natural) | Organism: Ruminococcus bromii L2-63 (bacteria) |
| Molecular weight | Theoretical: 135.6 KDa |
-Macromolecule #1: Ruminococcus bromii Amy4
| Macromolecule | Name: Ruminococcus bromii Amy4 / type: protein_or_peptide / ID: 1 Details: removal of secretion peptide and dockerin domain, addition of a C-terminal 6x-His Tag Number of copies: 1 / Enantiomer: LEVO / EC number: alpha-amylase |
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| Source (natural) | Organism: Ruminococcus bromii L2-63 (bacteria) / Strain: L2-63 |
| Molecular weight | Theoretical: 135.745984 KDa |
| Recombinant expression | Organism: ![]() |
| Sequence | String: MGATVSDDSS TSASSTAAGS LVEDDGFTWD NANVYFLLTD RFKNGNTAND HSYGRTLDKD GKPLEGWDTN PGTFHGGDFA GVTQSIEEG YFDNLGVNAI WISAPYEQTH GYCDSGKGFA HYSYHGYYVL DYTETDANFG TKEEFKTLVD TAHEHGIRVI M DIVMNHTG ...String: MGATVSDDSS TSASSTAAGS LVEDDGFTWD NANVYFLLTD RFKNGNTAND HSYGRTLDKD GKPLEGWDTN PGTFHGGDFA GVTQSIEEG YFDNLGVNAI WISAPYEQTH GYCDSGKGFA HYSYHGYYVL DYTETDANFG TKEEFKTLVD TAHEHGIRVI M DIVMNHTG YNTVADMEQF GFGTLLDGAL DFKYKLTDVG EVNDHIDYKT SEEDWGKWWS NDWIRSGLPG YTEGAGGDLT MS LSGLPDF RTEQTKDVTI PPILKTKWTQ EGTYAQKLAK YGDKNTVTGY LSTWLSEWVR EYGVDGFRCD TAKHVDKASW NQL KQACVS ALREWRSNNK GKAGADWKED FWMTGEHWDH GVGYDTYYSE GGFDSMINFA VTGGGALASG SVANTYQGYA DKIN TKEGF NVLSFMSSHD ETLTRGDENT MLYNAAAFLL LPGGVQIFYG DETNRPLYPG VAFDGYGGSG HALRSDMNWN DMDKT LLAQ WQKVGQFRNK HVSIGAGANV KLSATSGVAF GRTYDKNGVT DQAAAVIGCN KNSSVTVDVS TLWEDGSYVI NTYDNS SSV VTDGKVTFNS GVNGTILMEN ADGQPLVSIT GEPKFYGTEQ VTVSLKECDS AKVSVDGGNK FVVKDGDTFT IGQTAYK ND TIEVTVEATN DKASSEAKFT FLKLGENDEK PTTSPTQSTT VPGSTASQTS KLTIKSTAGA PNVYAWTGAS TALNGAWP G QKAAAVSGQA NTYELTLPVS ADKSFSVVLN NGSGSQSGDI TGLYDGAVLE IQNGNYASVK TVTNGNQQGG GGEPEPAEG SVSVTIKPYS PSASYKIYAW NDTQKLTGAW PGVALTEKDS DGNYVVKFDN VDEVSIILSS GSGQTADITG VRDGATIEIT NEGCTTYKL TSKPIVVSPY ESLKKEARKI LAMTASDYTA ESWANAQKVL KSAEAMIKAG EDATTAEDMN AMIADLKSAQ K ALVLAPAT LTYAVVGKSV VSGVTASAAK VTVTVDGKTY TATADDVTGA FTVATSALKG TSTIKVDATR NGVNGTYSYA MK NGNIENG FVPTSPTLPT QPTTSTQPTT ATQPTTATQP TAPTQPTTAT EPTTAPAQKL TVNATSNYFG SASKTVSTDG KKV TVLYKL NSNMGVVDGQ WAVKYDSSKL KFNMADNKAD GKQTIMPSQS NLIHNAYSNV IKGVFTNPQV PTQYNGDTFI SLTF EVIGS GTASVYLDTQ YLTLGYVKGN KLNQASVVNN SKVCDVTGIA GFEKVSVNAS TAFVGDVTHH HHHH |
-Experimental details
-Structure determination
| Method | cryo EM |
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Processing | single particle reconstruction |
| Aggregation state | particle |
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Sample preparation
| Concentration | 0.3 mg/mL | ||||||||||||||||||
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| Buffer | pH: 7.4 Component:
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| Grid | Model: Quantifoil R1.2/1.3 / Material: GOLD / Mesh: 200 / Support film - Material: CARBON / Support film - topology: HOLEY / Pretreatment - Type: GLOW DISCHARGE / Pretreatment - Time: 45 sec. | ||||||||||||||||||
| Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 277 K / Instrument: FEI VITROBOT MARK IV |
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Electron microscopy
| Microscope | TFS KRIOS |
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| Image recording | Film or detector model: GATAN K3 (6k x 4k) / Number grids imaged: 1 / Number real images: 25000 / Average electron dose: 65.0 e/Å2 |
| Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
| Electron optics | C2 aperture diameter: 50.0 µm / Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Cs: 2.7 mm / Nominal defocus max: 2.4 µm / Nominal defocus min: 0.8 µm / Nominal magnification: 130000 |
| Sample stage | Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER / Cooling holder cryogen: NITROGEN |
| Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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Image processing
-Atomic model buiding 1
| Initial model | Chain - Source name: AlphaFold / Chain - Initial model type: in silico model / Details: full-length construct |
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| Refinement | Space: REAL / Protocol: FLEXIBLE FIT |
| Output model | ![]() PDB-9qf3: |
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About Yorodumi




Keywords
Ruminococcus bromii L2-63 (bacteria)
Authors
Switzerland, 1 items
Citation









Z (Sec.)
Y (Row.)
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FIELD EMISSION GUN

