reading.bits

These are notes that I gradually collect from my reading. @readingbits

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#virology #capsid #structure #glycoprotein

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#virology #capsid #structure #glycoprotein

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#virology #capsid #budding #capsid

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Herpes Simplex Virus Capsid:

The herpes viruses contain a nucleocapsid with an envelope. The capsid has holes in one of the proteins that acts as a portal for the DNA to get into the shell during assembly and out of the shell for infection. #virology #capsid #herpes

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The spike is made of 3 copies of a single protein. The tip of the spike proteins are held together by a single iron molecule. #virology #virus #spike #bacteriophage

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Bacteriophage Spike:

The image below shows a bacteriophage's spike that protrudes from the virusus' tail and penetrates the cell membrane before injecting the genetic material.

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Upon attachment to the cell, the baseplate penetrates the cell membrane and the genome is injected into the cell. #virology #tailed #bacteriophage

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Tailed Bacteriophages:

Tailed bacteriophages use a combination of a capsid attached to a helical tail attached to a baseplate. The genetic material is in the capsid stored under a high pressure.

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Rioviruses:

Rioviruses have two shells - inner and outer. #virology #capsid #riovirus

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Large Complex Capsids:

Below is an example of a large complex capsid with T=25. #virology #capsid

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T Number Examples:

The following are T number structure example: #virology #tnumber

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T Number:

The number of smallest triangular stuctures making up the triangular face of an icosahedron. #virology #capsid #structure #unit #tnumber #icosahedron

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Quasiequivalent bonding interactions: all engage in head to head and tail to tail interactions. 180 identical protein subunits in the example below. #virology #capsid #strucure #unit #pentamer #hexamer #icosahedron

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Larger Icosahedral Capsid:

Uses 3 different proteins. Made of pentamers and hexamers (unlike simple icosahedral capsids, which are made of pentamers only). Three modes of subunit packing (orange, yellow, purple).

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Simple Icosahedral Capsid:

Made of 60 identical subunits represented as commas in the image. Each subnit is an identical type of protein. Interactions of all molecules with their neighbors is identical (head to head, tail to tail). The particles are spherical, not icosahedral.

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Icosahedral symmetry:

Icosahedron is a platonic solid with 20 faces, each an equilateral triangle. It has 5x, 3x, and 2x axes of symmetry (12 each). Allows a formation of a small shell with smallest number (60) of identical subunits. #virology

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Caspar & Klug:

Caspar and Klug discovered in 1962 that round capsids are icosahedrons. Capsid subunits tended to be arranged as hexamers or pentamers.

#virology #capsid #strucure #unit #pentamer #hexamer #icosahedron

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Round Capsids:

All round capsids have precise number of proteins; multiples of 60 are common (60, 180, 240, 960).

#virology, #capsid, #structure, #unit

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Helical Viruses Envelope:

Turns out that all known animal helical structure viruses have a nucleocapsid with an envelope around it. Plant helical viruses don't have the envelope. They are made of capsids enclosing the RNA. #virology #capsid #nucleocapsid

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+ vs - Strand RNA Viruses:

The positive strand RNA viruses are ready to be translated when they enter the cell. The negative strand RNA viruses have to first be copied by the RNA polymerase that's in the virus particle. #virology #strands