Three-dimensional Reconstruction by Cryoelectron Microscopy of the Giant Hemoglobin of the Polychaete Worm Alvinella pompejana

A frozen-hydrated specimen of the hexagonal bilayer hemoglobin (HBL Hb) from the deep-sea hydrothermal vent polychaete worm Alvinella pompejana, the most thermophilic metazoan known to date, was observed in the electron microscope and subjected to three-dimensional (3D) reconstruction by the method...

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Bibliographic Details
Published in:Journal of molecular biology 1996-11, Vol.264 (1), p.111-120
Main Authors: de Haas, Felix, Zal, Franck, You, Valérie, Lallier, François, Toulmond, André, Lamy, Jean N.
Format: Article
Language:English
Subjects:
Alvinella pompejana
alvinellid
Animals
cryoelectron microscopy
Freezing
hemoglobin
Hemoglobins - chemistry
Hemoglobins - ultrastructure
hydrothermal vent
Image Processing, Computer-Assisted
Marine
Microscopy, Electron
Models, Molecular
Molecular Structure
Polychaeta
Polychaeta - chemistry
Protein Conformation
Species Specificity
structure
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Summary:A frozen-hydrated specimen of the hexagonal bilayer hemoglobin (HBL Hb) from the deep-sea hydrothermal vent polychaete worm Alvinella pompejana, the most thermophilic metazoan known to date, was observed in the electron microscope and subjected to three-dimensional (3D) reconstruction by the method of random conical tilt series. At a resolution of 34.6 Å by the differential phase residual method and 27.7 Å by the Fourier shell correlation method, the 3D volume possesses a D 6point-group symmetry. While in previous 3D reconstructions of annelid and vestimentiferan Hbs the vertices of the upper layer were 16° rotated compared with those of the lower layer, in AlvinellaHb the vertices of the two hexagonal layers are almost perfectly eclipsed when viewed along the 6-fold axis. As in the HBL Hbs of Riftia pachyptilaand Macrobdella decora, a central linker complex is decorated by 12 hollow globular substructures (HGS). The linker complex comprises (1) a central hexagonal toroid, (2) two internal bracelets onto which the HGSs are built, and (3) six connections between the two hexagonal layers. Each HGS is composed of six masses, which are separated when the volume is displayed at high threshold, plus one additional mass involved in the bracelet connecting the six HGSs in both hexagonal layers. The HGSs have a local pseudo 3-fold symmetry and a disposition of the high-density masses different from those of RiftiaV1 Hb.
ISSN:0022-2836
1089-8638
DOI:10.1006/jmbi.1996.0627