title: The herpes simplex virus DNA polymerase: analysis of the functional domains.
abstract: The structural and functional organization of the herpes simplex virus type I (HSV-1) DNA polymerase enzyme of strain ANG was studied by a combination of sequence and immunobiochemical analyses. Comparison of the HSV-1 ANG DNA polymerase sequence with those of pro- and eukaryotic DNA polymerases resulted in the allocation of eleven conserved regions within the HSV-1 DNA polymerase. From the analysis of all currently identified mutations of temperature-sensitive and drug-resistant HSV-1 DNA polymerase mutants as well as from the degree of conservancy observed, it could be deduced that the amino-acid residues 597-961, comprising the homologous sequence regions IV-IX, constitute the major structural components of the catalytic domain of the enzyme which should accommodate the sites for polymerizing and 3'-to-5' exonucleolytic functions. Further insight into the structural organization was gained by the use of polyclonal antibodies responding specifically to the N-terminal, central and C-terminal polypeptide domains of the ANG polymerase. Each of the antisera was able to immunostain as well as to immunoprecipitate a viral polypeptide of 132 +/- 5 kDa that corresponded well to the molecular mass of 136 kDa predicted from the coding sequences. Enzyme-binding and neutralization studies confirmed that both functions, polymerase and 3'-to-5' exonuclease, are intimately related to each other, and revealed that, in addition to the sequences of the proposed catalytic domain, the very C-terminal sequences, except for amino-acid residues 1072-1146, are important for the catalytic functions of the enzyme, most likely effecting the binding to DNA.
authors.affiliation: Institut für Virusforschung, Deutsches Krebsforschungszentrum, Heidelberg, F.R.G.
authors.forename: C W
authors.initials: CW
authors.lastname: Knopf
authors.forename: K
authors.initials: K
authors.lastname: Weisshart
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D002384:Catalysis; D004262:DNA Restriction Enzymes; D004259:DNA-Directed DNA Polymerase / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D043211:Exodeoxyribonuclease V; D005090:Exodeoxyribonucleases / Q000378:metabolism; D007106:Immune Sera / Q000494:pharmacology; D007163:Immunosorbent Techniques; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009154:Mutation; D010446:Peptide Fragments / Q000276:immunology; D012689:Sequence Homology, Nucleic Acid; D018139:Simplexvirus / Q000201:enzymology*; D013329:Structure-Activity Relationship
chemical_list: D007106:Immune Sera; D010446:Peptide Fragments; D004259:DNA-Directed DNA Polymerase; D005090:Exodeoxyribonucleases; D043211:Exodeoxyribonuclease V; D004262:DNA Restriction Enzymes