2018-08-22 REL PDBe PDBe PDBe 2016-12-24 2017-01-25 2018-08-22 2018-08-22 Busselez J Chichon FJ Melero R Carrascosa JL Carazo JM Busselez J Chichon FJ Rodriguez MJ Alpizar A Gharbi SI Franch M Melero R Paradela A Carrascosa JL Carazo JM To Be Published 0353 EMD-3557 associated EM volume EMD-3558 other EM volume

Centriolar proximal MT triplet from a mammal centrosome. Centrosomes were extracted from o.aries thymocytes

Centrosomes enriched from young lamb thymocyte Centrosomes enriched from young lamb thymocyte 0

The centrosomes were extracted accordingly to Komesli et. al. 1989

Ovis aries Thymus Thymus Lobules Centrosome cytoplasm near the nucleus 230000 Centriole 1 Ovis aries Thymus Thymus Lobules Centrosome cytoplasm near the nucleus subtomogramAveraging particle 0.076 7.2 10.0 C8H18N2O6S2 Pipes

pH Rectified with KOH

quantifoil 3.5/1 COPPER/RHODIUM 300 FORMVAR HOLEY ETHANE LEICA EM CPC

The sample was enriched by two step of sedimentation in sucrose gradient. The sucrose was washed out in several drops of buffer, the last of which included fiducial markers (10 nm bovine serum albumin (BSA)-coated gold beads) for tilt series alignment

FEI TITAN KRIOS OTHER BRIGHT FIELD FIELD EMISSION GUN 300 2.0 5.0 5.54 5.0 5.906 42000. FEI TITAN KRIOS AUTOGRID HOLDER NITROGEN Gatan 968 Quantum -10 10 GATAN K2 QUANTUM (4k x 4k) 3838 3710 1.0 1.4 1

Tilt series were aligned based on fiducials with IMOD and mass normalized using PRIISM. The ctf correction was processed on tilt series using TomoCTF. Tomogram were reconstructed using SIRT algorithm with TOMO3D. The number of frames per image were variable, with 8 frames at full tilt, through to 4 frames at zero tilt.

2 FOURIER SPACE 46.7 FSC 0.5 CUT-OFF Dynamo 1.1.22 413 4 1111 volume picked interactively Dynamo 1.1.22

coarse models of the centriole microtubules were obtained using Fiber Tracing in Amira and converted for import in dynamo. from those coarse models, "filament with torsion" models were traced in dynamo. the doublets were segregated from the triplets and doublets volume particles were windowed with overlap every 8.3nm along the filament with torsion models

TOMOCTF

wiener filtering, made on tilt series

4 Dynamo

classification by PCA+k-means

OTHER Dynamo 1.1.22

The particular geometry of the centriole with its repeat every 8.3nm along the proximal-distal axis and its coarse 9 fold symmetry was used to construct from each tomogram a coarse model lowly affected by missing wedge. Those coarse models where volume aligned and a initial reference were averaged from all the subtomogram particle using the coarse orientation of the particles determined in that way. This model was iteratively refined keeping for each iteration the particle with the 70% best cross-correlation to average the reference for the next-iteration. For the finer step a mask was used to restrict the alignment to 3 8.3nm repeats.

861.64 861.64 249.66 90 90 90 P1