Host cell metabolic energy is not required for injection of bacteriophage T5 DNA.
AUTOR(ES)
Filali Maltouf, A
RESUMO
The addition of various metabolic inhibitors (uncouplers, cyanide, arsenate, ionophores) separately or together (for example, arsenate and an uncoupler) or even harsher methods of energy depletion did not prevent bacteriophage T5 from injecting its first-step-transfer DNA (a DNA segment 3 micron long) into the cytoplasm of host cells. The same indifference to metabolic energy was observed if first-step-transfer DNA was decapsidated and uncoiled before injection, thus precluding any energetic help from the phage capsid or from some tension stored in DNA tightly packed in the head. Penetration of the second-step-transfer DNA across the cytoplasmic membrane was studied by determining injection of superinfecting T5 A2- amber phages into Sup- bacteria containing proteins A1 and A2 previously encoded by the first-step-transfer DNA of a primary wild-type phage. The addition of various metabolic inhibitors after synthesis of proteins A1 and A2 but before superinfection did not prevent this penetration of second-step-transfer DNA. Thus, we conclude that traversal of the cytoplasmic membrane by the entire T5 DNA (a molecule 34 micron long) must occur by diffusion through protein channels.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=217349Documentos Relacionados
- Requirement for a fluid host cell membrane in injection of coliphage T5 DNA.
- New physical map of bacteriophage T5 DNA.
- Distribution of "minor" nicks in bacteriophage T5 DNA.
- Role of the T5 gene D15 nuclease in the generation of nicked bacteriophage T5 DNA.
- Direction of transcription in bacteriophage T5 first-step transfer DNA.
