Regulation of filamentous bacteriophage length by modification of electrostatic interactions between coat protein and DNA.
J Mol Biol
; 217(2): 223-7, 1991 Jan 20.
Article
em En
| MEDLINE
| ID: mdl-1992159
ABSTRACT
Bacteriophage fd gene VIII, which encodes the major capsid protein, was mutated to convert the serine residue at position 47 to a lysine residue (S47K), thereby increasing the number of positively charged residues in the C-terminal region of the protein from four to five. The S47K coat protein underwent correct membrane insertion and processing but could not encapsidate the viral DNA, nor was it incorporated detectably with wild-type coat proteins into hybrid bacteriophage particles. However, hybrid virions could be constructed from the S47K coat protein and a second mutant coat protein, K48Q, the latter containing only three lysine residues in its C-terminal region. K48Q phage particles are approximately 35% longer than wild-type. Introducing the S47K protein shortened these particles, the S47K/K48Q hybrids exhibiting a range of lengths between those of K48Q and wild-type. These results indicate that filamentous bacteriophage length (and the DNA packaging underlying it) are regulated by unusually flexible electrostatic interactions between the C-terminal domain of the coat protein and the DNA. They strongly suggest that wild-type bacteriophage fd makes optimal use of the minimum number of coat protein subunits to package the DNA compactly.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
DNA Viral
/
Capsídeo
/
Colífagos
Idioma:
En
Ano de publicação:
1991
Tipo de documento:
Article