2024-03-20 REL RCSB RCSB RCSB 2023-11-14 2024-01-31 2024-01-31 2024-03-20 National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS) R35GM136656 United States National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS) R01GM026338 United States National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS) R01GM110530 United States Straight actin filament from Arp2/3 branch junction sample (ADP) Chavali SS Chou SZ Sindelar CV actin, arp2/3, cytoskeleton, branch, CYTOSOLIC PROTEIN Chavali SS Chou SZ Cao W Pollard TD De La Cruz EM Sindelar CV Cryo-EM structures reveal how phosphate release from Arp3 weakens actin filament branches formed by Arp2/3 complex. Nat Commun UK 15 2059 2059 2024 38448439 doi:10.1038/s41467-024-46179-x 2041-1723 EMD-42788 other EM volume
Arp2/3 branch complex (BeFx) from the same sample
 EMD-42787 other EM volume
Arp2/3 branch complex (ADP) from the same sample
 8uz0 FULLOVERLAP Actin Actin 0 1
Actin filament
Gallus gallus Actin, alpha skeletal muscle Oryctolagus cuniculus 0.04151633999999999 9 LEVO ETTALVCDNGSGLVKAGFAGDDAPRAVFPSIVGRPRHQGVMVGMGQKDSYVGDEAQSKRGILTLKYPIE(HIC)GIITNW DDMEKIWHHTFYNELRVAPEEHPTLLTEAPLNPKANREKMTQIMFETFNVPAMYVAIQAVLSLYASGRTTGIVLDSGDGV THNVPIYEGYALPHAIMRLDLAGRDLTDYLMKILTERGYSFVTTAEREIVRDIKEKLCYVALDFENEMATAASSSSLEKS YELPDGQVITIGNERFRCPETLFQPSFIGMESAGIHETTYNSIMKCDIDIRKDLYANNVMSGGTTMYPGIADRMQKEITA LAPSTMKIKIIAPPERKYSVWIGGSILASLSTFQQMWITKQEYDEAGPSIVHRKCF P68135 3.6.4.- ADENOSINE-5'-DIPHOSPHATE 0.000427201 9 ADP MAGNESIUM ION 2.4305e-05 9 MG helical particle 7.5 ETHANE 100 277 FEI VITROBOT MARK IV
The samples were incubated on the grid for 50 s and the extra solution was blotted using two Vitrobot filter papers (0.55/20 mm, Grade 595, Ted Pella) for 4 s at 0 blot force. The grids were plunged into liquid ethane at ~180 degrees C with a wait time of 0.5 s..
Actin monomers with bound Ca2+ were converted to Mg2+-actin by equilibrating with 50 micromolar MgCl2 and 0.2 mM EGTA (pH 7.5) for 10 min on ice. Actin was polymerized in the presence of capping protein (CP) by sequentially mixing 8.75 micromolar Mg-ATP-actin monomers with 0.75 micromolar CP and equilibrated at room temperature for 1 h. In parallel, Arp2/3 complex (0.4 micromolar) in QB buffer was activated by mixing 0.85 micromolar GCN4-VCA and 50 micromolar ATP and incubated at 4 degrees for 1 h. The capped actin filaments sample was then gently mixed with an equal volume of activated Arp2/3 complex sample using cut pipette tips and equilibrated at 4 degrees for 5 min. Daughter filaments were formed and elongated in the presence of CP by adding 0.25 micromolar Mg-actin monomers, 50 micromolar ATP, and 40 nM CP and incubated for 5 min at room temperature. This step was subsequently repeated 4 more times, then aged for ~90 min before preparing grids for cryo-EM data collection.
 FEI TITAN KRIOS FLOOD BEAM BRIGHT FIELD FIELD EMISSION GUN 300 2.7 1.2 2.5 64000.0 FEI TITAN KRIOS AUTOGRID HOLDER NITROGEN GIF Quantum LS 20
Electron micrographs for image reconstructions were collected using Titan Krios equipped with X-cold field emission gun at 300 kV, Gatan image filter with slit width of 20 eV and a nanoprobe.
The vitrified grids were screened for sample homogeneity and ice thickness in a Glacios 200 kV transmission electron microscope equipped with Gatan K2 summit camera. Electron micrographs for image reconstructions were collected using Titan Krios equipped with X-cold field emission gun at 300 kV, Gatan image filter with slit width of 20 eV and a nanoprobe.
GATAN K3 (6k x 4k) 8519 3.3 51.4
Each movie contains 41 frames with a frame time of 0.08 s. A dose rate of 28.4 counts/pixel/s and a physical pixel size of 1.346 Angstroms was used.
 1 27.42 -166.76 C1 2.8 FSC 0.143 CUT-OFF cryoSPARC 3.0
For the final 3D reconstruction, no helical symmetry was applied
490230 2320824 cryoSPARC filament
Low-pass filtered F-actin structure (20 A resolution)
 MAXIMUM LIKELIHOOD cryoSPARC 3.0 emd_42829.map.gz 1 IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) 256 256 256 0 0 0 256 256 256 344.576 344.576 344.576 90.0 90.0 90.0 X Y Z -2.21349 4.047427 0.001347616 0.117038645 1.346 1.346 1.346 0.4 EMDB Helical F-actin from Arp2/3 branch complex (ADP) emd_42829_half_map_1.map.gz 1 IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) 256 256 256 0 0 0 256 256 256 344.576 344.576 344.576 90.0 90.0 90.0 X Y Z -0.40264598 1.4434628 0.00064822624 0.06161281 1.346 1.346 1.346 AUTHOR Helical F-actin from Arp2/3 branch complex (ADP) emd_42829_half_map_2.map.gz 1 IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) 256 256 256 0 0 0 256 256 256 344.576 344.576 344.576 90.0 90.0 90.0 X Y Z -0.40959728 1.4565583 0.00064949045 0.06154284 1.346 1.346 1.346 AUTHOR Helical F-actin from Arp2/3 branch complex (ADP)