Alanine-scanning mutagenesis reveals a cytosine deaminase mutant with altered substrate preference

Biochemistry
Sheri D MahanM E Black

Abstract

Suicide gene therapy of cancer is a method whereby cancerous tumors can be selectively eradicated while sparing damage to normal tissue. This is accomplished by delivering a gene, encoding an enzyme capable of specifically converting a nontoxic prodrug into a cytotoxin, to cancer cells followed by prodrug administration. The Escherichia coli gene, codA, encodes cytosine deaminase and is introduced into cancer cells followed by administration of the prodrug 5-fluorocytosine (5-FC). Cytosine deaminase converts 5-FC into cytotoxic 5-fluorouracil, which leads to tumor-cell eradication. One limitation of this enzyme/prodrug combination is that 5-FC is a poor substrate for bacterial cytosine deaminase. The crystal structure of bacterial cytosine deaminase (bCD) reveals that a loop structure in the active site pocket of wild-type bCD comprising residues 310-320 undergoes a conformational change upon cytosine binding, making several contacts to the pyrimidine ring. Alanine-scanning mutagenesis was used to investigate the structure-function relationship of amino acid residues within this region, especially with regard to substrate specificity. Using an E. coli genetic complementation system, seven active mutants were identified (F310A, ...Continue Reading

References

Jan 1, 1992·Proceedings of the National Academy of Sciences of the United States of America·C A MullenR M Blaese

❮ Previous
Next ❯

Citations

Jun 8, 2012·Applied Biochemistry and Biotechnology·Vinod Kumar YataSiddhartha Sankar Ghosh
Sep 21, 2011·Proceedings of the National Academy of Sciences of the United States of America·Chapman M WrightMarc Ostermeier
Jul 8, 2011·World Journal of Gastroenterology : WJG·Long-Ying DengLi-Zong Shen
Apr 11, 2007·Bioscience, Biotechnology, and Biochemistry·Yoshinori HamajiShun'ichiro Taniguchi
Aug 27, 2014·Bioconjugate Chemistry·Stacy E MartinMargaret E Black
Oct 30, 2013·The Plant Journal : for Cell and Molecular Biology·Ayako Nishizawa-YokoiSeiichi Toki
May 22, 2013·Journal of Controlled Release : Official Journal of the Controlled Release Society·Panos LehouritisMark Tangney
Feb 23, 2008·Journal of Molecular Biology·Tiffany S StolworthyMargaret E Black
Jan 21, 2015·Frontiers in Plant Science·Zenpei ShimataniRie Terada
Oct 24, 2018·Frontiers in Microbiology·Agota AučynaitėJaunius Urbonavičius
Jan 25, 2006·Molecular Cancer Therapeutics·Yoram BarakA Matin
Nov 23, 2006·Journal of the American Chemical Society·Cong LiZaver M Bhujwalla

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.