- Library Home /
- Search Collections /
- Open Collections /
- Browse Collections /
- UBC Theses and Dissertations /
- The biosynthesis of N-putrescinylthymine in bacteriophage...
Open Collections
UBC Theses and Dissertations
UBC Theses and Dissertations
The biosynthesis of N-putrescinylthymine in bacteriophage φW-14 infected Pseudomonas acidovorans Karrer, Earl
Abstract
The biosynthesis of N-putrescinylthymine (NpT), a modified pyrimi-dine which occurs in the DNA of phage φW-14, was studied. Prior to this study, the metabolism of arginine and polyamines in the host organism, Pseudomonas acidovorans 29, was investigated. P. acidovorans transported ornithine and arginine but not putrescine. Neither amino acid was used as a sole source of nitrogen. Thus arginine cannot be catabolized to putrescine and ornithine is not catabolized to γ-aminobutyrate. Ornithine was synthesized from glutamate but the operation of this pathway was not inhibited by high concentrations of arginine. Since ornithine was decarboxylated to putrescine, this single route for the synthesis of polyamines is unusual in that ornithine biosynthesis is constitutive. P. acidovorans and φW-14 contain an unusual complement of polyamines: spermidine, putrescine and 2-hydroxyputrescine. Their respective bacterial concentrations (mM) were: 3-5, 50 and 45, phage infection led to an increase in the proportion of putrescine. ¹⁴C-Ornithine was used to label NpT in phage DNA. ¹⁴C-5-Ornithine exclusively labelled NpT, whereas ¹⁴C-1-ornithine was totally ineffective in this capacity. Hence, the carboxyl group of ornithine is not a constituent of the NpT molecule. Labelling of NpT with ¹⁴C-3-serine demonstrated a tetrahydrofolate (THF) involvement in its biosynthesis. The use of ³H-2,3-serine showed that N¹⁰methylene THF was the carbon donor for the pyrimidine precursor of NpT. It is proposed that NpT is synthesized in the following way: 5-hydroxymethyl deoxyuridine monophosphate is formed by the interaction of N¹⁰ methylene THF and deoxyuridine monophosphate; putrescine then condenses with the hydroxymethyl group of the nucleotide to yield N-putrescinyl-thymine.
Item Metadata
Title |
The biosynthesis of N-putrescinylthymine in bacteriophage φW-14 infected Pseudomonas acidovorans
|
Creator | |
Publisher |
University of British Columbia
|
Date Issued |
1973
|
Description |
The biosynthesis of N-putrescinylthymine (NpT), a modified pyrimi-dine which occurs in the DNA of phage φW-14, was studied. Prior to this study, the metabolism of arginine and polyamines in the host organism, Pseudomonas acidovorans 29, was investigated.
P. acidovorans transported ornithine and arginine but not putrescine. Neither amino acid was used as a sole source of nitrogen. Thus arginine cannot be catabolized to putrescine and ornithine is not catabolized to γ-aminobutyrate. Ornithine was synthesized from glutamate but the
operation of this pathway was not inhibited by high concentrations of arginine.
Since ornithine was decarboxylated to putrescine, this single route for the synthesis of polyamines is unusual in that ornithine biosynthesis
is constitutive.
P. acidovorans and φW-14 contain an unusual complement of polyamines: spermidine, putrescine and 2-hydroxyputrescine. Their respective bacterial concentrations (mM) were: 3-5, 50 and 45, phage infection led to an increase
in the proportion of putrescine.
¹⁴C-Ornithine was used to label NpT in phage DNA. ¹⁴C-5-Ornithine
exclusively labelled NpT, whereas ¹⁴C-1-ornithine was totally ineffective in this capacity. Hence, the carboxyl group of ornithine is not a constituent
of the NpT molecule.
Labelling of NpT with ¹⁴C-3-serine demonstrated a tetrahydrofolate (THF) involvement in its biosynthesis. The use of ³H-2,3-serine showed that N¹⁰methylene THF was the carbon donor for the pyrimidine precursor of
NpT. It is proposed that NpT is synthesized in the following way: 5-hydroxymethyl deoxyuridine monophosphate is formed by the interaction of N¹⁰ methylene THF and deoxyuridine monophosphate; putrescine then condenses
with the hydroxymethyl group of the nucleotide to yield N-putrescinyl-thymine.
|
Genre | |
Type | |
Language |
eng
|
Date Available |
2011-03-24
|
Provider |
Vancouver : University of British Columbia Library
|
Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
|
DOI |
10.14288/1.0101418
|
URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
|
Campus | |
Scholarly Level |
Graduate
|
Aggregated Source Repository |
DSpace
|
Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.