The expression of thymidine kinase in fungi, which normally lack this enzyme, will greatly aid the study of DNA metabolism and provide useful drug-sensitive phenotypes. The herpes simplex virus type-1 thymidine kinase gene ( tk ) was expressed in Neurospora crassa. tk was expressed as a fusion to N.crassa arg-2 regulatory sequences and as a hygromycin phosphotransferase-thymidine kinase fusion ...

Crystal structures of equine herpesvirus type-4 thymidine kinase (EHV4-TK) in complex with (i). thymidine and ADP, (ii). thymidine and SO(4) and the bisubstrate analogs, (iii). TP(4)A, and (iv). TP(5)A have been solved. Additionally, the structure of herpes simplex virus type-1 thymidine kinase (HSV1-TK) in complex with TP(5)A has been determined. These are the first structures of nucleoside ki...

The limitations of the ganciclovir (GCV)/herpes simplex virus thymidine kinase (HSV1 TK: EC 2.7.1.21) system as a suicide gene therapy approach have been extensively studied over the years. In our study, we focused on improving the cytotoxic profile of the GCV/equine herpes virus-4 thymidine kinase (EHV4 TK: EC 2.7.1.21) system. Our approach involved the structure-guided mutagenesis of EHV4 TK ...

background: recent research on several dna fragments covering open reading frames (orf) 1-37 shows a new genetic marker in orf 6 which is specific for differentiating wild-type varicella-zoster virus (vzv) strains from oka varicella vaccine strain. on the other hand, herpes simplex virus (hsv) genome analysis by restriction enzymes is used to differentiate types one and two of the virus and eve...

The thymidine kinases (TK) of alphaherpesviruses phosphorylate nucleosides, allowing viral replication in non-dividing cells. They also phosphorylate acyclovir (ACV), a specific antiviral when modified. Despite encoding a TK homolog, Kaposi’s sarcoma-associated herpesvirus (KSHV), a gammaherpesvirus, is relatively immune to the effects of ACV. In this issue, Gill et al (2015) show that rather t...

The pLE2SCX vector was developed for the stable expression of exogenous genes in the protozoan parasite Leishmania. The pLE2SCX construct contains three independent selection markers: herpes simplex virus thymidine kinase (HSV-TK), cytosine deaminase (CD) and streptothericin acetyltransferase gene (sat) in multiple cloning site, flanking by 5’ and 3’ untranslated regions of the previously clone...

the ple2scx vector was developed for the stable expression of exogenous genes in the protozoan parasite leishmania. the ple2scx construct contains three independent selection markers: herpes simplex virus thymidine kinase (hsv-tk), cytosine deaminase (cd) and streptothericin acetyltransferase gene (sat) in multiple cloning site, flanking by 5’ and 3’ untranslated regions of the previously clone...

Novel N1-substituted thymine derivatives related to 1-[(Z)-4-(triphenylmethoxy)-2-butenyl]thymine have been synthesized and evaluated against thymidine kinase-2 (TK-2) and related nucleoside kinases [i.e., Drosophila melanogaster deoxynucleoside kinase (Dm-dNK) and herpes simplex virus type 1 thymidine kinase (HSV-1 TK)]. The thymine base has been tethered to a distal triphenylmethoxy moiety th...

It is known that the Herpes simplex virus type 1 (HSV-1)-encoded thymidine kinase (TK) co-purifies with an associated thymidylate kinase (TMPK) activity and that thymidylate (TMP) inhibits the phosphorylation of thymidine by the HSV-1 TK. Here we demonstrate that: (i) TMP phosphorylation catalysed by the viral TMPK is competitively inhibited by thymidine (TdR) with a Ki equal to its Km as subst...