Folate is an important micronutrient found in green vegetables, fruits and beans. The synthetic form that is added to foods and found in supplements is known as folic acid (FA). FA plays an essential role in several complex metabolic pathways including DNA synthesis and pathways that are involved in the methionine metabolic pathway, which is crucial for DNA methylation (Fenech et al., 2001; Eic...

A low molecular weight DNA polymerase (DNA nucleotidyltransferase; EC 2.7.7.7) has been purified 265,000-fold from ovaries of the frogXertopus Zuevis. On polyacrylamide gels run under denaturing conditions the purified preparation exhibited one major band of approximately 45,000 molecular weight. The most purified fraction incorporated 380 pmol of dTMP/h/mg of protein at 26”. No endodeoxyribonu...

Folate availability is critical for DNA integrity, required for the transfer of methyl groups in the biosynthesis of thymidilate. Reduction of 5,10-methylenetetrahydrofolate, a donor for methylating dUMP to dTMP in DNA synthesis, to 5-methyltetrahydrofolate, the primary methyl donor for methionine synthesis, is catalyzed by 5,10-methylenetetrahydrofolate reductase (MTHFR). The MTHFR polymorphis...

Kaposi's sarcoma-associated herpesvirus (KSHV) is a highly infectious human herpesvirus that causes Kaposi's sarcoma. KSHV encodes functional thymidylate synthase, which is a target for anticancer drugs such as raltitrexed or 5-fluorouracil. Thymidylate synthase catalyzes the conversion of 2'-deoxyuridine-5'-monophosphate (dUMP) to thymidine-5'-monophosphate (dTMP) using 5,10-methylenetetrahydr...

A low molecular weight DNA polymerase (DNA nucleotidyltransferase; EC 2.7.7.7) has been purified 265,000-fold from ovaries of the frogXertopus Zuevis. On polyacrylamide gels run under denaturing conditions the purified preparation exhibited one major band of approximately 45,000 molecular weight. The most purified fraction incorporated 380 pmol of dTMP/h/mg of protein at 26”. No endodeoxyribonu...

Genome instability is a hallmark of cancer cells. One class of genome aberrations prevalent in tumor cells is termed gross chromosomal rearrangements (GCRs). GCRs comprise chromosome translocations, amplifications, inversions, deletion of whole chromosome arms, and interstitial deletions. Here, we report the results of a genome-wide screen in Saccharomyces cerevisiae aimed at identifying novel ...

A random population of temperature-sensitive mutants was screened by assaying for defects in DNA synthesis in a permeabilized yeast DNA replication system. Twenty mutants defective in in vitro DNA synthesis have been isolated. In this paper we describe eight of these mutants. Seven of them fall into three complementation groups--cdc2, cdc8, and cdc16--involved in the control of the cell-divisio...

Two RNA phosphoramidites containing the bases 1,N(6)-ethenoadenine (εA) and 3,N(4)-ethenocytosine (εC) were synthesized. These building blocks were incorporated into two 12-mer oligoribonucleotides for evaluation of the base pairing properties of these base lesions by UV melting curve (Tm) and circular dichroism measurements. The Tm data of the resulting duplexes with the etheno modifications o...

Unusual N-acetylated sugars have been observed on the O-antigens of some Gram-negative bacteria and on the S-layers of both Gram-positive and Gram-negative bacteria. One such sugar is 3-acetamido-3,6-dideoxy-α-d-galactose or Fuc3NAc. The pathway for its production requires five enzymes with the first step involving the attachment of dTMP to glucose-1-phosphate. Here, we report a structural and ...

Polynucleotide templates were copied by avian myeloblastosis virus DNA polymerase ("reverse transcriptase") and the frequency and distribution of errors were determined. The error rate with [r(pA)2500-d(pT)12-18] template-initiator under a variety of conditions was approximately 1/600, i.e. one incorrect dCMP incorporated for 600 correct dTMP polymerized. Addition of the metal chelator o-phenan...