scholarly journals Crystallization and preliminary X-ray analysis of thePlasmodium falciparumapicoplast DNA polymerase

2015 ◽  
Vol 71 (3) ◽  
pp. 333-337 ◽  
Author(s):  
Morgan E. Milton ◽  
Jun-yong Choe ◽  
Richard B. Honzatko ◽  
Scott W. Nelson
Keyword(s):  
Dna Polymerase ◽  
Structural Information ◽  
Klenow Fragment ◽  
X Ray Diffraction ◽  
Dna Polymerase I ◽  
X Ray ◽  
Cell Parameters ◽  
A Genome ◽  
Reported Data ◽  
Polymerase I

Infection by the parasitePlasmodium falciparumis the leading cause of malaria in humans. The parasite has a unique and essential plastid-like organelle called the apicoplast. The apicoplast contains a genome that undergoes replication and repair through the action of a replicative polymerase (apPOL). apPOL has no direct orthologs in mammalian polymerases and is therefore an attractive antimalarial drug target. No structural information exists for apPOL, and the Klenow fragment ofEscherichia coliDNA polymerase I, which is its closest structural homolog, shares only 28% sequence identity. Here, conditions for the crystallization of and preliminary X-ray diffraction data from crystals ofP. falciparumapPOL are reported. Data complete to 3.5 Å resolution were collected from a single crystal (2 × 2 × 5 µm) using a 5 µm beam. The space groupP6522 (unit-cell parametersa=b= 141.8,c= 149.7 Å, α = β = 90, γ = 120°) was confirmed by molecular replacement. Refinement is in progress.

scholarly journals Crystallization and preliminary X-ray diffraction analysis of a single variable domain of the immunoglobulin superfamily in amphioxus,Amphi-IgSF-V

2014 ◽  
Vol 70 (8) ◽  
pp. 1072-1075 ◽  
Author(s):  
Bo Jiang ◽  
Yanjie Liu ◽  
Rong Chen ◽  
Zhenbao Wang ◽  
Mansoor Tariq ◽  
...  
Keyword(s):  
Immune System ◽  
Structural Information ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Immunoglobulin Superfamily ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
System A ◽  
Human Immunoglobulins

Amphioxus is regarded as an essential animal model for the study of immune evolution. Discovery of new molecules with the immunoglobulin superfamily (IgSF) variable (V) domain in amphioxus would help in studying the evolution of IgSF V molecules in the immune system. A protein was found which just contains only one IgSF V domain in amphioxus, termedAmphi-IgSF-V; it has over 30% sequence identity to the V domains of human immunoglobulins and mammalian T-cell receptors. In order to clarify the three-dimensional structure of this new molecule in amphioxus,Amphi-IgSF-V was expressed, purified and crystallized, and diffraction data were collected to a resolution of 1.95 Å. The crystal belonged to space groupP3221, with unit-cell parametersa=b= 53.9,c= 135.5 Å. The Matthews coefficient and solvent content were calculated to be 2.58 Å3 Da−1and 52.38%, respectively. The results will provide structural information to study the evolution of IgSF V molecules in the immune system.

How E. coli DNA polymerase I (klenow fragment) distinguishes between deoxy- and dideoxynucleotides

1998 ◽  
Vol 278 (1) ◽  
pp. 147-165 ◽  
Author(s):  
Mekbib Astatke ◽  
Nigel D.F Grindley ◽  
Catherine M Joyce
Keyword(s):  
Dna Polymerase ◽  
Klenow Fragment ◽  
Dna Polymerase I ◽  
E Coli ◽  
Polymerase I

scholarly journals DNA polymerase I is required for premeiotic DNA replication and sporulation but not for X-ray repair in Saccharomyces cerevisiae

1989 ◽  
Vol 9 (2) ◽  
pp. 365-376
Author(s):  
M E Budd ◽  
K D Wittrup ◽  
J E Bailey ◽  
J L Campbell
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Replication ◽  
Dna Polymerase ◽  
Temperature Sensitive ◽  
Dna Polymerase I ◽  
X Ray ◽  
Temperature Sensitive Mutants ◽  
Polymerase I ◽  
Dna Polymerase Ii

We have used a set of seven temperature-sensitive mutants in the DNA polymerase I gene of Saccharomyces cerevisiae to investigate the role of DNA polymerase I in various aspects of DNA synthesis in vivo. Previously, we showed that DNA polymerase I is required for mitotic DNA replication. Here we extend our studies to several stages of meiosis and repair of X-ray-induced damage. We find that sporulation is blocked in all of the DNA polymerase temperature-sensitive mutants and that premeiotic DNA replication does not occur. Commitment to meiotic recombination is only 2% of wild-type levels. Thus, DNA polymerase I is essential for these steps. However, repair of X-ray-induced single-strand breaks is not defective in the DNA polymerase temperature-sensitive mutants, and DNA polymerase I is therefore not essential for repair of such lesions. These results suggest that DNA polymerase II or III or both, the two other nuclear yeast DNA polymerases for which roles have not yet been established, carry out repair in the absence of DNA polymerase I, but that DNA polymerase II and III cannot compensate for loss of DNA polymerase I in meiotic replication and recombination. These results do not, however, rule out essential roles for DNA polymerase II or III or both in addition to that for DNA polymerase I.

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