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Open data
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Basic information
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Title | Cryo-EM structure of Stanieria sp. CphA2 | |||||||||
![]() | Stanieria sp. CphA2 locally filtered map | |||||||||
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![]() | cyanophycin / CphA2 / ligase / ATP-grasp | |||||||||
Function / homology | ![]() ribosomal S6-glutamic acid ligase activity / SOS response / ATP binding / metal ion binding / cytoplasm Similarity search - Function | |||||||||
Biological species | ![]() ![]() | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 2.8 Å | |||||||||
![]() | Markus LM / Sharon I / Strauss M / Schmeing TM | |||||||||
Funding support | ![]()
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![]() | ![]() Title: Structure and function of a hexameric cyanophycin synthetase 2. Authors: Linda M D Markus / Itai Sharon / Kim Munro / Marcel Grogg / Donald Hilvert / Mike Strauss / T Martin Schmeing / ![]() ![]() Abstract: Cyanophycin is a natural polymer composed of a poly-aspartate backbone with arginine attached to each of the aspartate sidechains. Produced by a wide range of bacteria, which mainly use it as a store ...Cyanophycin is a natural polymer composed of a poly-aspartate backbone with arginine attached to each of the aspartate sidechains. Produced by a wide range of bacteria, which mainly use it as a store of fixed nitrogen, it has many promising industrial applications. Cyanophycin can be synthesized from the amino acids Asp and Arg by the widespread cyanophycin synthetase 1 (CphA1), or from the dipeptide β-Asp-Arg by the cyanobacterial enzyme cyanophycin synthetase 2 (CphA2). CphA2 enzymes display a range of oligomeric states, from dimers to dodecamers. Recently, the crystal structure of a CphA2 dimer was solved but could not be obtained in complex with substrate. Here, we report cryo-EM structures of the hexameric CphA2 from Stanieria sp. at ~2.8 Å resolution, both with and without ATP analog and cyanophycin. The structures show a two-fold symmetrical, trimer-of-dimers hexameric architecture, and substrate-binding interactions that are similar to those of CphA1. Mutagenesis experiments demonstrate the importance of several conserved substrate-binding residues. We also find that a Q416A/R528G double mutation prevents hexamer formation and use this double mutant to show that hexamerization augments the rate of cyanophycin synthesis. Together, these results increase our mechanistic understanding of how an interesting green polymer is biosynthesized. | |||||||||
History |
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Structure visualization
Supplemental images |
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Downloads & links
-EMDB archive
Map data | ![]() | 22.4 MB | ![]() | |
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Header (meta data) | ![]() ![]() | 14 KB 14 KB | Display Display | ![]() |
FSC (resolution estimation) | ![]() | 17 KB | Display | ![]() |
Images | ![]() | 64 KB | ||
Masks | ![]() | 512 MB | ![]() | |
Filedesc metadata | ![]() | 5.5 KB | ||
Others | ![]() ![]() | 474.2 MB 474.2 MB | ||
Archive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 8fxhMC ![]() 8fxiC M: atomic model generated by this map C: citing same article ( |
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Similar structure data | Similarity search - Function & homology ![]() |
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Links
EMDB pages | ![]() ![]() |
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Related items in Molecule of the Month |
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Map
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Annotation | Stanieria sp. CphA2 locally filtered map | ||||||||||||||||||||||||||||||||||||
Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 0.675 Å | ||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
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-Supplemental data
-Mask #1
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Density Histograms |
-Half map: Stanieria sp. CphA2 half map A
File | emd_29533_half_map_1.map | ||||||||||||
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Annotation | Stanieria sp. CphA2 half map A | ||||||||||||
Projections & Slices |
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Density Histograms |
-Half map: Stanieria sp. CphA2 half map B
File | emd_29533_half_map_2.map | ||||||||||||
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Annotation | Stanieria sp. CphA2 half map B | ||||||||||||
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Density Histograms |
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Sample components
-Entire : Stanieria sp. CphA2
Entire | Name: Stanieria sp. CphA2 |
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Components |
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-Supramolecule #1: Stanieria sp. CphA2
Supramolecule | Name: Stanieria sp. CphA2 / type: complex / ID: 1 / Parent: 0 / Macromolecule list: all |
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Source (natural) | Organism: ![]() |
-Macromolecule #1: RimK domain-containing protein ATP-grasp
Macromolecule | Name: RimK domain-containing protein ATP-grasp / type: protein_or_peptide / ID: 1 / Number of copies: 6 / Enantiomer: LEVO |
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Source (natural) | Organism: ![]() |
Molecular weight | Theoretical: 72.886516 KDa |
Recombinant expression | Organism: ![]() ![]() |
Sequence | String: MLTKQAVEPV RINARTTDVF DIFNVKQYVG ANPYLNQAAL VFDFAFTESY QPLPIENYLA VVGDRYPRLK EIEYQSYAEL FASTVAEVN KLEMDLHLKG WNVKPIEEIN RIAIESLHHR TTKEVVYCVW DWFEFITQGE EFDLSKQIAI LQQLFRNSVY G GPTVYALL ...String: MLTKQAVEPV RINARTTDVF DIFNVKQYVG ANPYLNQAAL VFDFAFTESY QPLPIENYLA VVGDRYPRLK EIEYQSYAEL FASTVAEVN KLEMDLHLKG WNVKPIEEIN RIAIESLHHR TTKEVVYCVW DWFEFITQGE EFDLSKQIAI LQQLFRNSVY G GPTVYALL RTANEKHIPA FYLWDEGLMQ YGYGKQQVRG IATTFDVDSH IDSDFTTQKD DCKKFLQELG FPVPQGDVVF SL AEAKEVA AEIGYPVAVK PVAGHKGIGV TADVQDEIEL EAAYDRAVAG IPLEEKICII VENSIAGHDY RLLCVNGRFV AAT ERKPAY VVGDGYSTIA ELIEKENFSP NRSDTPTSPM GKIRTDEAMH LYLEEQGLDL DSVIDRDRTI YLRKVANLSS GGFS IDATN RVHPDNIILA QDIAQHFRLT CLGIDIITND IGRSWKETSF GIIEINAAPG VYMHLKPAIG EPVDVTARIL ETFFE TEKN ARIPIITFNR VSIRQLQKLS DRILMSHPDW TIGAVCREGI LINRSEKILN RHYNTNVLNL LRNPKLDLLI AEYDED ALE AEGMFYHGSN LVVLEDPSEI EMILTRDVFS DSTVIIKQGR EITIKRKGLL EQYELEAEEL IEQVYLKEIG TISENLY FQ UniProtKB: RimK domain-containing protein ATP-grasp |
-Experimental details
-Structure determination
Method | cryo EM |
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![]() | single particle reconstruction |
Aggregation state | particle |
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Sample preparation
Buffer | pH: 7.5 |
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Vitrification | Cryogen name: ETHANE |
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Electron microscopy
Microscope | FEI TITAN KRIOS |
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Image recording | Film or detector model: GATAN K3 BIOQUANTUM (6k x 4k) / Average electron dose: 80.0 e/Å2 |
Electron beam | Acceleration voltage: 300 kV / Electron source: ![]() |
Electron optics | Illumination mode: SPOT SCAN / Imaging mode: BRIGHT FIELD / Nominal defocus max: -0.0025 µm / Nominal defocus min: -0.001 µm |
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |