A model for reverse transcription by a dimeric enzyme.

A speculative model for reverse transcription of a viral RNA template into proviral dsDNA is presented. It has two essential features that are not included in current models: (i) the functional complex is dimeric, with two polymerization/RNase H sites and (ii) two templates are initially attached to the complex at their 3' ends. The model also has the optional features that (iii) the complex is rotationally symmetrical and (iv) attached to the virion core. The model attempts to explain why the viral genome is dimeric, the specificity of the 'jumps' between the ends of templates and how recombination occurs so readily. It also suggests novel targets for drug therapy during retroviral infection, for example, in AIDS.