Anatomy of a shape-shifting virus

All viruses naturally mutate when they replicate, changing the genome – the genetic blueprint – that enables a virus to function. The British coronavirus variant B117 has now spread to more than 30 countries

Coronavirus
Human host cell
ACE2* receptor
Infection: Virus relies onspike glycoprotein to bind to ACE2 receptor – entry point intohuman cell for virus to replicate 

Spike protein (S)
Genome
Nucleocapsid (N)
Capsid proteincoat surrounds ribonucleic acid genome (RNA)
Membrane (M)
Envelope (E)

B117: Has altered receptor binding domain known as N501Y situated on spike protein. Mutation allows easier access to ACE2 receptor

Change increases transmissibility by up to 70% – children now more susceptible to virus

*Angiotensin-converting enzyme 2

Genome: Of 17 amino acid mutations, eight affect spike protein
N501Y: Amino acid asparagine replaced by amino acid tyrosine

ORF 1a†
ORF 1b†
Spike
E
M
N

Rocketing case rates from new variant (positive swab tests, percent)
Jan 6, 2021: One person in every 50 in England now has Covid-19. In London one in 30 is infected
Nov 11  ENGLAND 1.22 LONDON 0.99
Nov 18 1.16 0.83 
Nov 25 0.96 0.72
Dec 02 0.88 0.90
Dec 09 1.04 1.45
Dec 15 1.18 2.13
Dec 18 1.30 2.54
†ORF – Open reading frame: Allows host cell’s molecular machine – its ribosomes – to read RNA code and add amino acids one after another to make viral protein

Sources: Covid-19 Genomics Consortium UK, Bloomberg, NCBI, ONS
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