Biomaterial Database

Identification of the primase active site of the herpes simplex virus type 1 helicase-primase. 1995

S Dracheva, and E V Koonin, and J J Crute

Department of Immunological Diseases, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut 06877-0368, USA.

Herpes simplex virus type 1 (HSV-1) encodes a heterotrimeric helicase-primase composed of the products of the three DNA replication-specific genes UL5, UL8, and UL52 (Crute, J. J., and Lehman, I. R. (1991) J. Biol. Chem. 266, 4484-4488). The UL5 and UL52 products constitute a heterodimeric subassembly of the holoenzyme that contains both helicase and primase activities (Calder, J. M., and Stow, N. D. (1990) Nucleic Acids Res. 18, 3573-3578; Dodson, M. S., and Lehman, I. R. (1991) Proc. Natl. Acad. Sci. U. S. A. 88, 1105-1109). The role of the UL52 product in the active HSV-1 helicase-primase was examined. A sequence located between residues 610 and 636 on the UL52 protein was found to be conserved among the UL52 homologues of eight herpesviruses. The carboxyl-terminal portion of this conserved sequence consisted of two Asp residues separated by a variable hydrophobic amino acid residue and is analogous to the divalent metal-binding site of DNA polymerases and several DNA primases. This motif has been designated the herpesvirus primase DXD motif. To study the role of the HSV-1 primase DXD motif in primase action, three site-directed changes were introduced into the UL52 gene. The helicase activity of the recombinant holoenzymes was unaffected by any of the introduced changes. Changing either of the two Asp residues that constitute the divalent metal-binding site (Asp628 or Asp630) to Ala dramatically reduced the primase activity of the HSV-1 helicase-primase holoenzyme in vitro, whereas alteration of the nearby conserved residue Asn624 to Gly had minimal effect. Therefore, in the three-subunit HSV-1 helicase-primase, the UL52 product provides at least a part of the primase catalytic site.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D004265	DNA Helicases	Proteins that catalyze the unwinding of duplex DNA during replication by binding cooperatively to single-stranded regions of DNA or to short regions of duplex DNA that are undergoing transient opening. In addition, DNA helicases are DNA-dependent ATPases that harness the free energy of ATP hydrolysis to translocate DNA strands.	ATP-Dependent DNA Helicase,DNA Helicase,DNA Unwinding Protein,DNA Unwinding Proteins,ATP-Dependent DNA Helicases,DNA Helicase A,DNA Helicase E,DNA Helicase II,DNA Helicase III,ATP Dependent DNA Helicase,ATP Dependent DNA Helicases,DNA Helicase, ATP-Dependent,DNA Helicases, ATP-Dependent,Helicase, ATP-Dependent DNA,Helicase, DNA,Helicases, ATP-Dependent DNA,Helicases, DNA,Protein, DNA Unwinding,Unwinding Protein, DNA,Unwinding Proteins, DNA
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining
D012316	RNA Nucleotidyltransferases	Enzymes that catalyze the template-directed incorporation of ribonucleotides into an RNA chain. EC 2.7.7.-.	Nucleotidyltransferases, RNA
D018259	Herpesvirus 1, Human	The type species of SIMPLEXVIRUS causing most forms of non-genital herpes simplex in humans. Primary infection occurs mainly in infants and young children and then the virus becomes latent in the dorsal root ganglion. It then is periodically reactivated throughout life causing mostly benign conditions.	HSV-1,Herpes Simplex Virus 1,HHV-1,Herpes Simplex Virus Type 1,Herpesvirus 1 (alpha), Human,Human Herpesvirus 1
D019915	DNA Primase	A single-stranded DNA-dependent RNA polymerase that functions to initiate, or prime, DNA synthesis by synthesizing oligoribonucleotide primers. EC 2.7.7.-.	Primase,Bacteriophage T7 Gene 4 Protein,DnaG (Primase),DnaG Gene Product,DnaG Protein,T7 DNA Primase-Helicase Protein,T7 DNA-Priming Protein,T7 gene-4 protein,DNA-Priming Protein, T7,Primase, DNA,Protein, T7 DNA-Priming,T7 DNA Primase Helicase Protein,T7 DNA Priming Protein,T7 gene 4 protein