DNA of Myxococcus phage MX-1. Pyrimidine isostichs and the recognition of a minor pyrimidine
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Abstract:
DNA was isolated from bacteriophage MX-1 and was hydrolysed with acids. Hydrolysis with 90% formic acid produced several interconvertable fluorescent artefacts. These substances were produced in greater quantity following hydrolysis with H2SO4. In the course of the course of the study it was found that DNA extracted from phage by 4-aminosalicylate and phenol contained 4-aminosalicylate and breakdown products derived from 4-aminosalicylate following acid hydrolysis. Pyrimidine oligonucleotides released by formic acid-diphenylamine hydrolysis were fractionated by two-dimensional paper chromatography and by ion-exchange chromatography. In this way, the pyrimidine isostichs were obtained and further fractionated. The distribution and with isostich patterns from a variety of DNA sources. MX-1 DNA was found to contain an unusually high frequency of cytosine-rich isostichs 5 and 6 and very low occurrence of the sequence R-Y-R. Based on its absorption spectrum and the fact that it can be labelled in vivo with [14C] orotic acid, we suggest that H-base is a pyrimidine.
Insights
Researchers analyzed DNA from bacteriophage MX-1, identifying fluorescent artifacts from acid hydrolysis and unusual pyrimidine oligonucleotide patterns. These findings offer insights into DNA structure and degradation products.
Area of Science:
- Molecular Biology
- Biochemistry
Background:
- DNA analysis often involves acid hydrolysis, which can produce artifacts.
- Understanding DNA composition, particularly pyrimidine oligonucleotide distribution, is crucial for molecular studies.
Purpose of the Study:
- To investigate DNA degradation products from bacteriophage MX-1 using acid hydrolysis.
- To characterize the pyrimidine oligonucleotide composition of MX-1 DNA.
Main Methods:
- DNA isolation from bacteriophage MX-1.
- Acid hydrolysis (formic acid, H2SO4) and analysis of fluorescent artifacts.
- Pyrimidine oligonucleotide fractionation using two-dimensional paper chromatography and ion-exchange chromatography.
- Analysis of isostich patterns and DNA base composition.
Main Results:
- Acid hydrolysis, particularly with formic acid and H2SO4, generated interconvertable fluorescent artifacts.
- DNA extracted using 4-aminosalicylate and phenol contained 4-aminosalicylate breakdown products.
- MX-1 DNA exhibited an unusually high frequency of cytosine-rich isostichs (5 and 6) and a low occurrence of the R-Y-R sequence.
- Evidence suggests an unidentified 'H-base' is a pyrimidine.
Conclusions:
- Acid hydrolysis can introduce artifacts that complicate DNA analysis.
- Bacteriophage MX-1 DNA has a distinct pyrimidine oligonucleotide composition.
- Further characterization of DNA degradation products and novel bases is warranted.