Access Type

Open Access Thesis

Date of Award

January 2014

Degree Type


Degree Name




First Advisor

Ashok S. Bhagwat


The AID/APOBEC enzymes are DNA/RNA cytosine deaminases with important functions in innate and adaptive immunity. APOBEC3 enzymes play a crucial role in restricting the replication of exogenous retroviruses such HIV-1 and endogenous retrotransposition events. In particular, APOBEC3 enzymes have evolved in humans by gene duplication to compose seven members. APOBEC3H is highly diverse in its allelic sequence and the distribution is population-specific. It has evolved under strong positive selection over millions of years. To study the catalytic mechanism, structure, function and the underlying cause of its high diversity, a high resolution crystal or NMR structure is required are not yet available. The human APOBEC3H splice variant 183 was purified as an N-terminally poly-histidine tagged construct and it was tested for biochemical activity as the first step in characterizing the enzyme.