Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Microbubbles in replicating nuclear deoxyribonucleic acid from Physarum polycephalum.

ABSTRACT: Clusters of microbubbles, represent probable sites of newly initiated DNA synthesis, were identified in nuclear DNA from Physarum polycephalum by using the electron microscope. Their presence is associated specifically with S-phase. Each microbubble corresponds in size to a replicating segment of DNA about 100-5000 nucleotide residues in length. The DNA structures containing microbubbles are metastable, and revert to native DNA in the presence of moderate concentrations of formamide used to prepare samples for electron microscopy. It is suggested that each cluster of microbubbles may correspond to a unit of replication (a replicon) in Physarum DNA.

SUBMITTER: Gillespie DA

PROVIDER: S-EPMC1161582 | biostudies-other | 1979 Nov

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Sequence organization in nuclear deoxyribonucleic acid from Physarum polycephalum. Physical properties of foldback sequences.

Project description:An investigation was performed with the use of physical techniques, to determine the nature and organization of inverted repeat sequences in nuclear DNA fragments from Physarum polycephalum. From the average size of foldback duplexes (550 nucleotide pairs), and the foldback duplex yield as determined by treatment of DNA with S1 deoxyribonuclease followed by hydroxyapatite chromatography, it is estimated that there are at least 25000 foldback sequences in the Physarum genome. Foldback DNA molecules exhibit properties intermediate between single-stranded DNA and native duplexes on elution from hydroxyapatite with a salt gradient. In addition, thermal-elution chromatography of foldback DNA from hydroxyapatite crystals shows that foldback duplexes are less stable than native DNA. These properties can be explained on the basis that inverted repeat sequences are mismatched when in the foldback configuration. The results of experiments in which the binding of foldback DNA molecules to hydroxyapatite was determined, by using fragments of different single-chain size, agree with previous studies indicating that inverted repeat sequences are located, on average, every 7000 residues throughout the Physarum genome. The inverted repeats are derived from both the repetitive and single-copy components in Physarum nuclear DNA.

| S-EPMC1162497 | biostudies-other

The heterogeneity of cytoplasmic deoxyribonucleic acid polymerase from Physarum polycephalum.

Project description:Cytoplasmic DNA polymerase (DNA deoxynucleotidyltransferase, EC 2.7.7.7) was partially purified from Physarum polycephalum. The first step of the purification procedure utilized the fact that the enzyme on gel filtration behaves in anomalous fashion. The second step was either ion-exchange chromatography or sucrose-density-gradient centrifugation. The partially purified DNA polymerase was heterogeneous and at least four species with different sedimentation coefficients (5.5S, 7.2S, 8.6S and 11.5S) were detected. Calculated molecular weights indicated a tendency for stoicheiometric polypeptide aggregation, accompanied by an alteration of the three-dimensional structure froma compact spheroid to a more open elliptical form. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and computed molecular weights suggest an active protomer in the range of 113000 daltons; all data pertain to I 0.045, which was maintained during the whole procedure.

| S-EPMC1183974 | biostudies-other

Physarum polycephalum

Project description:An EST sequencing project has begun for this organism

| PRJNA12701 | ENA

Physarum polycephalum

Project description:This slime mold is brightly colored, yellow, and can become quite large

| PRJNA12700 | ENA

Physarum polycephalum

Project description:De novo RNA-Seq analytisis of plasmodia and sclerotia from Physarum polycephalum.

| PRJDB11632 | ENA

Physarum polycephalum

Project description:Physarum polycephalum transcript analysis

| PRJNA79513 | ENA

Physarum polycephalum

Project description:RNA-seq characterization of Physarum macroplasmodia

| PRJNA148107 | ENA

Physarum polycephalum

Project description:Complete characterization of the edited transcriptome of the mitochondrion of Physarum polycephalum using deep sequencing of RNA

| PRJNA79923 | ENA

Physarum polycephalum

Project description:Physarum polycephalum

| PRJNA12851 | ENA

Physarum polycephalum

Project description:Physarum Genome project

| PRJDB4281 | ENA