Diaz-Mitoma, F.,Zeibdawi, Abdul-Rahman.2009-03-192009-03-1919971997Source: Masters Abstracts International, Volume: 36-01, page: 0121.9780612209862http://hdl.handle.net/10393/4122http://dx.doi.org/10.20381/ruor-13589I have examined the fidelity of both the DNA-dependent DNA polymerase and the RNA-dependent DNA polymerase activities of five different forms of recombinant HIV-1 reverse transcriptase (RT). The DNA synthesis fidelity assay was based on the frequency with which mutations were introduced into the lacZ gene of Escherichia coli (E. coli). RNA and DNA of the lacZ reporter sequence were used as templates for DNA synthesis and the frequency of mutation was determined by the frequency of appearance of light blue or colorless colonies of E. coli on reporter plates. My results show that these enzymes are active and are error-prone during synthesis in vitro with DNA and RNA templates. Overall, fidelity of synthesis from an RNA template is lower than that from a DNA template. Sequence analysis of mutants generated with the two substrates reveal that base substitutions are random, whereas deletions and insertions are base specific. 'Hot spots' are observed with the mature form (p66/p51) of RT but not with the precursor forms of RT. In both DNA and RNA-dependent DNA synthesis, the mature form of the RT (p66/p51) has the highest error rate and the precursors have significantly lower error rates. In addition, the HIV-1 integrase domain appears to confer higher fidelity to the mature p66/p51 polymerase. I propose that the RT precursor plays a significant role in the replication of the virus and that the hypermutability observed with the virus is a result of multiple factors which include RT and selection for surviving mutants. (Abstract shortened by UMI.)89 p.Biology, Molecular.Thesis