Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.1.21 (thymidine kinase)
 7,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this paper we present the nucleotide sequences of the thymidine kinase (TK) genes of two avian herpesviruses: a highly oncogenic strain of Marek's disease virus (MDV strain RB1B) and its serologically related vaccine virus, the herpesvirus of turkeys (HVT strain Fc-126). The predicted coding regions of the two genes are 1029 and 1050 nucleotides respectively, corresponding to polypeptides of 343 and 350 amino acids in length. Putative nucleotide- and nucleoside-binding sites have been identified within the two predicted amino acid sequences. The MDV and HVT TK amino acid sequences exhibit 58.2% amino acid identity. Comparison with other available herpesvirus TK sequences reveals a greater homology to those of the alphaherpesviruses than to those of the gammaherpesviruses. No overall homology was found when compared with the chicken cytoplasmic TK sequence.
J Gen Virol 1989 Nov
PMID:Nucleotide and predicted amino acid sequences of the Marek's disease virus and turkey herpesvirus thymidine kinase genes; comparison with thymidine kinase genes of other herpesviruses. 255 35

The precise genomic location and the nucleotide sequence of the bovine herpesvirus type 2 (bovine herpes mammillitis virus) thymidine kinase (TK) gene have been determined. The genomic location of the TK gene was found to be in a similar position to that of herpes simplex virus. The coding region consists of 918 bases, which is slightly smaller in length than other reported herpesvirus TK genes. However with an Mr of 38,108 the individual protein is similar in size to other herpesvirus TK enzymes. Despite there being only limited overall sequence homology with the TK genes of other herpesviruses, there are several regions of extensive homology at the amino acid level.
J Gen Virol 1989 Nov
PMID:Location and characterization of the bovine herpesvirus type 2 thymidine kinase gene. 255 36

We have extended previous comparisons of genetic organization between poxvirus genera by sequencing a 2.5K genomic fragment from isolate KS-1 (Kenya sheep-1) of the genus capripoxvirus. The fragment is located in the central region of the capripoxvirus genome and contains three complete and two incomplete open reading frames (ORFs). One of the complete ORFs is a gene for thymidine kinase (TK). This gene, with one of the other two complete ORFs and both the incomplete ORFs, are homologous to four contiguous ORFs from the central region of vaccinia virus (VV) DNA. They also match four ORFs of fowlpox virus (FPV) DNA, three of which are contiguous and the fourth, the FPV TK gene, is located elsewhere on the FPV genome. The third complete ORF of the capripoxvirus DNA fragment is located between the TK gene and the capripoxvirus homologue of the ORF immediately downstream of the VV TK gene. We show that a homologue to this third ORF is absent from VV and FPV DNAs, but is present downstream of the TK gene on Shope fibroma virus DNA. The sequence immediately upstream of the capripoxvirus homologue of a VV late gene contains a motif which is required for VV late gene expression. The motif required for VV early gene transcription termination is present in eight positions in the capripoxvirus sequence, and five of these positions are consistent with the motif having an equivalent function in capripoxvirus to that in VV.
J Gen Virol 1989 Mar
PMID:The nucleotide sequence around the capripoxvirus thymidine kinase gene reveals a gene shared specifically with leporipoxvirus. 273

The location of a promoter (PF) in the HindIII F region of the vaccinia virus genome was mapped by introducing deletions into this region of the DNA. Modified promoters were fused to the herpes simplex virus (HSV) thymidine kinase (TK) gene in plasmids facilitating the construction of recombinant vaccinia viruses, and promoter function was monitored by the ability of such plasmids to rescue TK+ vaccinia viruses from cells infected with TK- virus. Deletions from the 3' end of the promoter region produced mutants for which function was either not inhibited or abolished, allowing the 3' promoter boundary to be defined to within 13 nucleotides. As indicated by the presence of the PF transcript in early RNA and the kinetics of HSV TK expression in recombinant vaccinia viruses, transcription from PF occurred primarily at early times during infection. The major transcript was initiated at a site within 20 nucleotides of the 3' end of the promoter and nine bases upstream of the probable translation initiation codon. In one mutant for which a small but reproducible increase in promoter function was detected, the transcription start site was deleted. Nevertheless, transcription still appeared to begin at the equivalent position with respect to the promoter, despite the altered nucleotide sequence. The location of the start site for the PF transcript indicated that the HSV TK gene, inserted at the BamHI site following the promoter, was preceded by an initiation codon which could potentially attenuate expression of the inserted gene. Conversion of this ATG codon to TAG did not significantly improve HSV TK expression.
J Gen Virol 1987 Sep
PMID:Effect of in vitro mutations in a vaccinia virus early promoter region monitored by herpes simplex virus thymidine kinase expression in recombinant vaccinia virus. 282 Nov 71

Herpes simplex virus type 1 (HSV-1) strains F, HF and HFEM were studied with respect to pathogenicity in mice and growth characteristics in vivo and in vitro compared to the neurovirulent HSV-1 strains 17 syn+ and KOS. All three viruses demonstrated reduced virulence in mouse brains and were completely avirulent after footpad inoculation. They were shown to express high levels of thymidine kinase activity. Investigations concerning the virulence phenotype indicated that the defect(s) in strains F, HF and HFEM related to general replication deficiency in mouse cells. It was also shown that although the replication restriction observed for strains F and HF was specific for murine cells, strain HFEM did not replicate well in any cell type tested. Additional studies indicated that the avirulence phenotype which followed peripheral inoculation was related to different genotypes, since strain F complemented HF and HFEM and, as expected, the latter two agents did not complement each other. All three agents were found to complement the non-neuroinvasive strain KOS. Finally, the data also show that two herpesviruses which are highly restricted in murine cells (e.g. strains F and HF) can still interact in the animal and produce a lethal infection.
J Gen Virol 1987 Sep
PMID:Biological basis for virulence of three strains of herpes simplex virus type 1. 282 Nov 78

In mice, intravenous inoculation of relatively avirulent strains of herpes simplex virus [e.g. P2C6, a mutant of strain CL(101), deficient in thymidine kinase] produced infection in the adrenal gland and mid-spinal cord followed by hind limb paralysis without death. Male mice were less susceptible to paralysis than female mice. Castration of male mice before inoculation increased their susceptibility to that of female animals; treatment with testosterone reversed this change. The differences in susceptibility to paralysis in the various categories of animal were not reflected in differences in growth of virus in the adrenal gland or spinal cord.
J Gen Virol 1987 Sep
PMID:The influence of androgens on paralysis in mice following intravenous inoculation of herpes simplex virus. 282 Nov 83

The experiments described in the present work were designed to study the function of the N-terminal end of thymidine kinase (TK) encoded by herpes simplex virus type 1. Specifically we were interested to know whether this end was involved in binding of the enzyme to other molecules, had any influence on its subcellular localization or affected one or more of the activities associated with the enzyme. A parental enzyme and a deletion mutant, lacking the 45 N-terminal amino acids, derived from this strain, were used. Thymidine kinase from the parental virus bound to DNA-Sepharose, but the truncated enzyme did not. This was apparently not due to a specific ability to bind to DNA, since immunofluorescence studies indicated that both the normal and the deleted TK were mainly located in the cytoplasm, preferentially in the perinuclear region. Phosphorylation of thymidine as well as the amounts of TK polypeptides were markedly reduced at late times after infection with the mutant, but not to the same extent after infection with the wild-type. The deleted TK gene was efficiently transcribed as shown by hybridization of RNA to a probe specific for the gene, and this RNA directed the synthesis in vitro of TK polypeptides. Deletion of the 5' end of the gene seems to affect the stability of either the enzyme or TK-specific mRNA, or both. The TMP phosphorylating activity seems to be particularly destabilized relative to the thymidine phosphorylating activity.
J Gen Virol 1987 Nov
PMID:Evidence that deletion of coding sequences in the 5' end of the thymidine kinase gene of herpes simplex virus type 1 affects the stability of the gene products. 282 63

The effect of nucleoside-5-triphosphates analogues on the DNA polymerase of herpes simplex virus (HSV) has been investigated. Evidence is obtained that 3-amino-2,3-dideoxythymidine triphosphate selectively inhibits the DNA synthesis, catalyzed by HSV DNA polymerase. 3-amino-2,3-dideoxythymidine exhibits antiherpetic effect in single cells cultures. It may be phosphorylated by cellular thymidine kinase. The nuclei of Vero cells infected by HSV are an adequate system for antiherpetic compounds screening.
Mol Gen Mikrobiol Virusol 1987 Oct
PMID:[Inhibitory effect of various analogs of nucleoside-5'-triphosphates on DNA synthesis catalyzed by DNA polymerase from herpes simplex virus type I]. 282 34

A 2 micron circle-based chimaeric plasmid containing the yeast LEU2 and the Herpes Simplex Virus type 1 thymidine kinase (HSV-1 TK) genes was constructed. Transformants grown under selective conditions for the LEU2 gene harboured the plasmid at about 15 copies per cell whilst selection for the HSV-1 TK gene led to an increase to about 100 copies per cell. Furthermore, the plasmid copy number could be controlled by the stringency of selection for the TK gene, and the increase in TK gene dosage was reflected in an increase in intracellular thymidine kinase activity. The mitotic stability of the plasmid in "high-copy" and "low-copy" number cells was determined. "High-copy" number cells showed a greater mitotic stability. The relationship of TK expression to plasmid copy number may be useful for the isolation of plasmid copy number mutants in yeast and the control of heterologous gene expression.
Mol Gen Genet 1988 Jan
PMID:Amplification of plasmid copy number by thymidine kinase expression in Saccharomyces cerevisiae. 283 Apr 62

The DNA sequence of a clustered set of genes which are conserved in orthopoxviruses has been determined for the avipoxvirus, fowlpox virus. The arrangement of the genes in fowlpox virus is nearly identical to that in vaccinia virus, and genes which are overlapping in vaccinia virus overlap in fowlpox virus. One major difference exists however, as the thymidine kinase (TK) gene is absent in fowlpox virus from the position it occupies within this cluster of genes in vaccinia virus. Instead, in fowlpox virus there is a 32 bp non-coding region present between the genes that flank the TK gene in vaccinia virus. The fowlpox virus TK gene has been cloned and sequenced. The sequences immediately flanking the TK gene show no homology to any previously reported poxvirus gene. These results are discussed in terms of genome stability in poxviruses and the use of the TK gene as a non-essential region for the introduction of foreign genes into poxviruses.
J Gen Virol 1988 Jun
PMID:Comparison of a conserved region in fowlpox virus and vaccinia virus genomes and the translocation of the fowlpox virus thymidine kinase gene. 283 74


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