Retroviral reverse transcriptases (other than those of HIV-1 and murine leukemia virus): A comparison of their molecular and biochemical properties

This chapter reviews most of the biochemical data on reverse transcriptases (RTs) of retroviruses, other than those of HIV-1 and murine leukemia virus (MLV) that are covered in detail in other reviews of this special edition devoted to reverse transcriptases. The various RTs mentioned are grouped according to their retroviral origins and include the RTs of the alpharetroviruses, lentiviruses (both primate, other than HIV-1, and non-primate lentiviruses), betaretroviruses, deltaretroviruses and spumaretroviruses. For each RT group, the processing, molecular organization as well as the enzymatic activities and biochemical properties are described. Several RTs function as dimers, primarily as heterodimers, while the others are active as monomeric proteins. The comparisons between the diverse properties of the various RTs show the common traits that characterize the RTs from all retroviral subfamilies. In addition, the unique features of the specific RTs groups are also discussed.