alexa Temperature-sensitive mutants of Corynebacterium ammoniagenes ATCC 6872 with a defective large subunit of the manganese-containing ribonucleotide reductase.
Pharmaceutical Sciences

Pharmaceutical Sciences

Journal of Bioequivalence & Bioavailability

Author(s): Luo C, Hansen J, Auling G

Abstract Share this page

Abstract Chemical mutagenesis of the nucleotide-producing strain Corynebacterium ammoniagenes ATCC 6872 with N-methyl-N-nitro-N-nitrosoguanidine followed by an enrichment protocol yielded 46 temperature-sensitive (ts) clones. A rapid assay for the allosterically regulated Mn-ribonucleotide reductase (RRase) was developed with nucleotide-permeable cells of C. ammoniagenes in order to screen for possible defects in DNA precursor biosynthesis at elevated temperature. Three mutants (CH 31, CH 32, and CH 33) grew well at 30 degrees C but did not proliferate at 40 degrees C because they did not reduce ribonucleotides to 2'-deoxyribonucleotides. They were designated nrdts (nucleotide reduction defective). When the cultures were shifted from 30 to 40 degrees C, the nrdts mutants immediately ceased to incorporate radiolabeled nucleic acid precursors into the DNA fraction, while DNA chain elongation was barely affected. Thus, exhaustion of the deoxyribonucleotide pool ultimately inhibited cell division, leading to a filamentous growth morphology. In contrast to the wild-type, all three nrdts mutants displayed a distinctly enhanced sensitivity of ribonucleotide reduction towards hydroxyurea (in permeabilized cells and in vitro) at 30 degrees C. The results from assays for biochemical complementation of heat-inactivated (2 min, 37 degrees C) mutant enzyme with either the small or the large subunit of wild-type Mn-RRase located the mutational defect on the large subunit.
This article was published in Arch Microbiol and referenced in Journal of Bioequivalence & Bioavailability

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Relevant Topics

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

Agri, Food, Aqua and Veterinary Science Journals

Dr. Krish

[email protected]

1-702-714-7001 Extn: 9040

Clinical and Biochemistry Journals

Datta A

[email protected]

1-702-714-7001Extn: 9037

Business & Management Journals

Ronald

[email protected]

1-702-714-7001Extn: 9042

Chemical Engineering and Chemistry Journals

Gabriel Shaw

[email protected]

1-702-714-7001 Extn: 9040

Earth & Environmental Sciences

Katie Wilson

[email protected]

1-702-714-7001Extn: 9042

Engineering Journals

James Franklin

[email protected]

1-702-714-7001Extn: 9042

General Science and Health care Journals

Andrea Jason

[email protected]

1-702-714-7001Extn: 9043

Genetics and Molecular Biology Journals

Anna Melissa

[email protected]

1-702-714-7001 Extn: 9006

Immunology & Microbiology Journals

David Gorantl

[email protected]

1-702-714-7001Extn: 9014

Informatics Journals

Stephanie Skinner

[email protected]

1-702-714-7001Extn: 9039

Material Sciences Journals

Rachle Green

[email protected]

1-702-714-7001Extn: 9039

Mathematics and Physics Journals

Jim Willison

[email protected]

1-702-714-7001 Extn: 9042

Medical Journals

Nimmi Anna

[email protected]

1-702-714-7001 Extn: 9038

Neuroscience & Psychology Journals

Nathan T

[email protected]

1-702-714-7001Extn: 9041

Pharmaceutical Sciences Journals

John Behannon

[email protected]

1-702-714-7001Extn: 9007

Social & Political Science Journals

Steve Harry

[email protected]

1-702-714-7001 Extn: 9042

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords