Electron microscope observations on λ bacteriophage ultrastructure
| Autor: | A. Mazza, B. Felluga |
|---|---|
| Rok vydání: | 1973 |
| Předmět: |
Morphology (linguistics)
Ultraviolet Rays Icosahedral symmetry Biology Coliphages Models Biological Defective virus law.invention Viral Proteins law Microscopy Centrifugation Density Gradient Escherichia coli Molecular Biology Staining and Labeling Capsomere Defective Viruses Phosphotungstic Acid Negative stain Microscopy Electron Crystallography Nucleoproteins DNA Viral Biophysics Ultrastructure Anatomy Electron microscope |
| Zdroj: | Journal of Ultrastructure Research. 45:259-278 |
| ISSN: | 0022-5320 |
| Popis: | Three strains of λ bacteriophage (wild, reference, and crypticogen) that differ in sedimentation velocity in preformed CsCl gradients were investigated by electron microscopy. Negative staining with or without SDS treatment was used to study details of ultrastructure both in full and in disrupted particles. Head morphology was similar in the three strains examined. The observed arrangement of morphological units (capsomeres) on the edges of a hexagonal outline, as well as in remnants of disrupted capsids, permits restriction of the possible total number of capsomeres in the head; with pentamer—hexamer clustering of morphological units, the most likely triangulation numbers seem to be T = 19 and T = 21. Marked variations in number and length of tails were shown by λ reference. Multitailed particles, not previously shown for λ bacteriophage, were seen. These are consistent with icosahedral λ head configuration. Continuous filamentlike structures observed in disrupted heads are consistent with known biochemical findings and suggest that the λ head is composed of more than one protein species. A ringlike structure is also shown in petit λ. Further details and sizes of the tail components are shown, and a detailed model for λ tail is proposed, that agree well with available biochemical findings. |
| Databáze: | OpenAIRE |
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