DNA Bacteriophage Structure and Assembly:

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DNA Bacteriophage Structure and Assembly
Tail Structure Assembly
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T4 life cycle
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T4 assembly pathway
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T4 tail structure
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Shortening gene 29 protein makes shorter tails
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Lengthening gene 29 protein makes longer tails
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Comparison of lambda and T4 tail tubes
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Micrographs of T4 tail tubes containing 5 key
proteins
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Gp29 fiber is visible on contracted tails and
whole phage
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T4 attachment and DNA injection
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T4 tail tubes may induce membrane fusion
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Tape Measure Proteins (TMPs)
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Head Assembly and Structure
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Thin section of infected cells
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Concept of an assembly core or scaffold
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Steps in head maturation
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Electron micrograph of proheads on cell membrane
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Micrographs of head size mutants
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Micrographs of head size mutants
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Sucrose gradient separation of head size mutants
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A theory for head length determination
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Vernier model for head length determination
In T4, the two vernier components (X, Y) would be
the scaffold protein gp22 and the shell protein
gp23
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Cryo electron micrograph of isometric T4 heads
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3D reconstruction, from cryo EM, of isometric T4
heads
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Depth coding by color of T4 head reconstruction
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Mechanisms of Virus Size Determination
1. Tape measure mechanism (one component) example
T4 tail 2. Vernier mechanism (two
components) example T4 head in progress
determination of details of molecular structure
of head by X-ray diffraction