Bacteriophages action

Cre is a bacterial recombinase (cre=causes recombination), which recognizes loxP sites of bacteriophage P. If two loxP (loxP= locus of x-ing over of bacteriophage P) sites have a parallel orientation, the DNA segment between these sites will be deleted by the action of the Cre recombinase. 

Autoradiography The detection of radioactive molecules (eg, DNA, RNA, protein) by visualization of their effects on photographic film. Bacteriophage A virus that infects a bacterium. Blunt-ended DNA Two strands of a DNA duplex having ends that are flush with each other. cDNA A single-stranded DNA molecule that is complementary to an mRNA molecule and is synthesized from it by the action of reverse transcriptase. 

In addition, they assist in replication of RNA viruses, another process that requires RNA synthesis. Viruses sometimes make use of host RNA polymerases but often synthesize their own catalytic subunits. Bacteriophage T4 uses the E. coli RNA polymerase and o factors but modifies their action through the binding of several phage-encoded proteins.248 In contrast, phage T7 encodes its own relatively simple RNAP whose initiation complex (Section A,2)29 and elongation complexes have been studied 249-249b... 

Weaver et al. (1985) noted some similarities in the active site of the three lysozymes, but with the following striking difference. Residue 73 (Glu) in goose corresponds with residue 35 (Glu) in chick and with residue 11 (Glu) in bacteriophage T4. On the other hand, there are two Asp residues at positions 86 and 97 in the goose active site, neither of which corresponds exactly with Asp-52 of chick nor Asp-20 of T4. The implications for potential differences in the mechanism of catalytic action by the three lysozymes were discussed by Johnson et al. (1988) and by et al. (1985). The latter authors discussed the unresolved question as to whether the c-type lysozyme exons correspond to distinct structural and/or functional entities that are conserved during evolution of the three types of lysozyme considered. 

The steroidal diamines, irehdiamine-A (244) (IDA) and malouetine (243) (MAL), exert an inhibiting action on the growth of bacteriophage T2 in infected cells of Escherichia coli. Bacteriophage-directed DNA synthesis is more sensitive to steroidal amine inhibition than RNA or protein synthesis, and it is proposed that DNA is the primary target of steroidal diamine action. 

The first suggestion that the strand cleavage reaction catalyzed endonuclease III from E. coli, UV endonuclease V from bacteriophage T4, and UV endonuclease from Micrococcus luteus did not proceed by a hydrolytic mechanism was that the sugar-phosphate end could not be removed by the action of the 3 5 ... 

---