Gp4 is a nuclease required for morphogenesis of T4-like bacteriophages.
Virology
; 543: 7-12, 2020 04.
Article
em En
| MEDLINE
| ID: mdl-32056848
ABSTRACT
An essential step in the morphogenesis of tailed bacteriophages is the joining of heads and tails to form infectious virions. Our understanding of the maturation of complete virus particles remains incomplete. Through an unknown mechanism, phage T4 gene product 4 (gp4) plays an essential role in the head-tail joining step of T4-like phages. Alignment of T4 gp4 homologs identified a type II restriction endonuclease motif. Purified gp4 from both T4 and a marine T4-like bacteriophage, YC, have non-specific nuclease activity in vitro. Mutation of a single conserved amino acid residue in the endonuclease fold of T4 and YC gp4 abrogates nuclease activity. When expressed in trans, the wild type T4 gp4, but neither the mutated T4 protein nor the YC homolog, rescues a T4 gene 4 amber mutant phage. Thus the nuclease activity appears essential for morphogenesis, potentially by cleaving packaged DNA to enable the joining of heads to tails.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
3_ND
Base de dados:
MEDLINE
Assunto principal:
Vírion
/
Capsídeo
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Bacteriófago T4
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Montagem de Vírus
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Proteínas do Capsídeo
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Endonucleases
Idioma:
En
Revista:
Virology
Ano de publicação:
2020
Tipo de documento:
Article