title: Computer analysis of retroviral pol genes: assignment of enzymatic functions to specific sequences and homologies with nonviral enzymes.
abstract: A computer analysis of the amino acid sequences from the putative gene products of retroviral pol genes has revealed a 150-residue segment that is homologous with the ribonuclease H of Escherichia coli. The segment occurs at the carboxyl terminus of the region assigned to the 90-kDa reverse transcriptase polypeptide. In contrast, a section nearer the amino terminus of this sequence can be aligned with nonretroviral polymerases. The order of activities in the pol gene is thus: polymerase-ribonuclease-endonuclease. On another note, all retroviral endonuclease sequences contain a consensus zinc-binding "finger." This should not be confused with the well-known zinc requirement of reverse transcriptases.
mesh_terms: D000595:Amino Acid Sequence; D003201:Computers; D004265:DNA Helicases / Q000032:analysis*; D004722:Endoribonucleases / Q000032:analysis*; D005814:Genes, Viral; D019426:Integrases; D012194:RNA-Directed DNA Polymerase / Q000032:analysis*; D012190:Retroviridae / Q000201:enzymology* / Q000235:genetics; D016914:Ribonuclease H; D014764:Viral Proteins / Q000032:analysis*
chemical_list: D014764:Viral Proteins; D019426:Integrases; D012194:RNA-Directed DNA Polymerase; D004722:Endoribonucleases; D016914:Ribonuclease H; D004265:DNA Helicases