Student Theses and Dissertations

Date of Award

1963

Document Type

Thesis

Degree Name

Doctor of Philosophy (PhD)

Thesis Advisor

Norton Zinder

Keywords

RNA bacteriophage, f2 growth, DNA independence, viral RNA synthesis, protein synthesis, phage-induced enzyme

Abstract

The growth of the RNA-containing bacteriophage f2 has been studied. DNA synthesis appears normal after phage infection. It is possible to dissociate the synthesis of viral RNA from the synthesis of DNA using thymine-less bacteria with fluorinated pyrimidines and Mitomycin C as inhibitors of DNA synthesis. It is concluded that the growth of f2 is independent of DNA synthesis. Since the phage RNA has no special characteristics, its synthesis has been followed by using p32 to label RNA which is eventually incorporated into virus particles. Using this method of measuring phage RNA synthesis, it has been shown that the material for the synthesis of the virus nucleic acid (Phosphorus) comes almost entirely from the components of the medium, and not from the host cell. Also, only 10% of the virus particles released from an infected cell can form plaques in the phage assay system. Chloramphenicol (CA) has been used to elucidate the relationship of protein synthesis to the synthesis of phage f2 RNA. Phage RNA synthesis is inhibited if CA is added within two minutes after infection. If CA is added at later times, some phage RNA is synthesized. Addition of CA 15 minutes after infection allows phage RNA to be synthesized in amounts similar to the amount synthesized in uninhibited cells. The protein coat of f2 does not contain the amino acid histidine. By using as host bacteria a strain which requires histidine and methionine, it was shown that the synthesis of f2 becomes independent of the presence of histidine halfway through the latent period, but remains dependent on the continued presence of methionine. These results suggest that a protein, other than the coat, is synthesized early after phage f2 infection, which is essential for the synthesis of virus RNA. An enzyme activity which catalyzes the incorporation of ribonucleoside triphosphates into an acid precipitable material appears after infection. It has a number of characteristics which indicate that it is a new phage induced enzyme.

Comments

A thesis presented to the faculty of The Rockefeller University in partial fulfillment of the requirements for the degree of Doctor of Philosophy

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Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License
This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 4.0 International License.

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