Bacteriophage T4 gene 42 encodes dCMP hydroxymethylase, an
enzyme unique to the deoxyribonucleotide metabolism of T-even
bacteriophages. To study biochemical and biophysical properties of
the enzyme, as well as the interaction of dCMP hydroxymethylase with
other DNA precursor biosynthetic enzymes in vitro, availability of large
amounts of the enzyme is...
Imbalanced deoxyribonucleoside triphosphate (dNTP) pools are mutagenic for DNA synthesis in both intact cells and cell-free replication systems. Almost certainly, such mutagenesis involves competition between correctly and incorrectly base-paired precursors at replication sites. However, there are certain differences between the intact cell and cell-free systems that do not always allow...
A crucial factor in determining the accuracy of DNA replication is
maintenance of a balanced supply of deoxyribonucleoside triphosphates
(dNTPs) at replication forks. Perturbation of dNTP biosynthesis can
induce dNTP pool imbalance with deleterious genetic consequences,
including increased mutagenesis, recombination, chromosomal
abnormalities and cell death. Using the T4 bacteriophage system,...
Although the Escherichia coli host has almost all of the enzymes necessary to
synthesize nucleotides needed for bacteriophage T4 DNA replication, phage genes
expressed early in infection encode enzymes for de novo DNA precursor biosynthesis
and salvage from degraded host DNA. Eight early enzymes and two host enzymes
comprise the...
Ribonucleotide reductase is an important enzyme in the control of
DNA replication within the cell. Ribonucleotide reductase exerts its
control through enzymatic reduction of nucleoside diphosphates. The
bacteriophage T4 enzyme is an example of the class of iron-requiring
reductases which also includes E. coli and mammalian ribonucleotide
reductases. The two...
The ability to faithfully replicate DNA is dependent upon the maintenance
and regulation of its precursors, the deoxyribonucleoside triphosphates.
Enzymes encoded by the bacteriophage T4 have been widely used as models
of biochemical processes. A body of evidence supports the concept that the
bacteriophage T4 enzymes involved in deoxyribonucleotide biosynthesis...
Circular dichroism (CD) spectra were obtained for bacteriophage T4 lysozyme and three of its mutants in the presence and absence of colloidal silica nanoparticles. Mutant lysozymes were produced by substitution of the isoleucine at position 3 with tryptophan, cysteine and leucine. Each substitution resulted in an altered structural stability, quantified...
The enzymes of dNTP synthesis in T4 infection associate to form a multienzyme complex, the T4 dNTP synthetase complex, facilitating the flow of metabolites en route to dNTPs, and their subsequent flow into DNA. Study of protein-protein interactions helps one to understand how the enzymes in the complex are organized...
With respect to a multienzyme complex of deoxyribonucleoside triphosphate (dNTP) synthesis somehow juxtaposed with DNA replication sites, our laboratory has demonstrated the existence of a multienzyme complex in T4-infected E. coli, named the T4 dNTP synthetase complex, but the idea of direct linkage of dNTP synthesis to DNA replication and...