Ada (protein)

Ada (protein)

Ada is an enzyme induced by treatment of bacterial cells with alkylating agents that mainly cause methylation damage. This phenomenon is called the adaptive response and hence the name. Ada is also called as O6 alkyl guanine transferase I (O6 AGT I) . Ada transfers the alkyl group from DNA bases and sugar-phosphate backbone to a cysteine residue inactivating itself. Consequently, it reacts stoichiometrically with its substrate rather than catalytically and is referred to as a suicide enzyme. Methylation of Ada protein converts it into a self transcriptional activator, inducing its own gene expression and the expression of other genes which together with Ada help the cells repair alkylation damage [2] . Ada removes the alkyl group attached to DNA bases like guanine (O6-alkyl guanine) or thymine (O4-alkyl thymine) and to the oxygen of the phosphodiester backbone of the DNA [1,3] . However, Ada shows greater preference for O6- alkyl guanine compared to either O4-thymine and alkylated phosphotriesters. Ada enzyme has two active sites, one for the alkylated guanines and thymines and the other for alkylated phosphotriesters [2] .

References
# Errol C. Friedberg, Graham C. Walker, Wolfram Siede, Richard D. Wood, Roger A. Schultz, Tom Ellenberger, DNA Repair and Mutagenesis, second edition, ASM press, ISBN 1-55581-319-4
# Lindahl,T.,B. Sedgwick, M.Sekiguchi, & Y.Nakabeppu.(1988) Regulation and expression of adaptive response to alkylating agents, annu.Rev.Biochem.57:133-157
# McCarthy,T.V., and T. Lindahl.(1985)Methyl phosphotriesters in alkylated DNA are repaired by the Ada regulatory protein of E.Coli, Nucleic Acids Res.13:2683-2698


Wikimedia Foundation. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • Ada — or ADA may refer to: People * St. Ada, a 7th century French abbess. *Ada, Countess of Atholl (died 1264) * Ada, Countess of Holland * Ada de Warenne, Countess of Northumbria and Huntingdon (d. 1178) * Ada of Caria, satrap deposed by her brother… …   Wikipedia

  • Ada Yonath — Ada E. Yonath (2009) Ada E. Yonath (* 22. Juni 1939 in Jerusalem) ist eine israelische Strukturbiologin am Weizmann Institut für Wissenschaften in Rechowot, Israel. Sie entwickelte Verfahren für die Kristallisation von …   Deutsch Wikipedia

  • Ada Yonath — Infobox Scientist image width = 150px name = Ada E. Yonath birth date = 22 June 1939 birth place = Jerusalem residence = Israel nationality = Israeli field = Crystallography work institution = Weizmann Institute of Science alma mater = Hebrew… …   Wikipedia

  • Soja protein Becej — Soja protein Bečej Logo de Soja protein Bečej Création 1978 Dates clés 2001 (privatisation) Personnages clés …   Wikipédia en Français

  • YONATH, ADA — (1939– ), Israeli chemist. Born in Jerusalem, Yonath received her B.Sc. in chemistry in 1962 and M.Sc. in biochemistry in 1964 from the Hebrew University of Jerusalem. After completing her Ph.D. studies at the Weizmann Institute of Science,… …   Encyclopedia of Judaism

  • Adaptive response — The adaptive response is a form of direct DNA repair in E. coli that is initiated against alkylation, particularly methylation, of guanine or thymine nucleotides or phosphate groups on the sugar phosphate backbone of DNA. Under sustained exposure …   Wikipedia

  • Low-carbohydrate diet — Low carbohydrate diets or low carb diets are dietary programs that restrict carbohydrate consumption usually for weight control or for the treatment of obesity. Foods high in digestible carbohydrates (e.g. bread, pasta) are limited or replaced… …   Wikipedia

  • Gene therapy — using an Adenovirus vector. A new gene is inserted into an adenovirull. If the treatment is successful, the new gene will make a functional protein. Gene therapy is the insertion, alteration, or removal of genes within an individual s cells and… …   Wikipedia

  • List of file formats — This is an incomplete list, which may never be able to satisfy particular standards for completeness. You can help by expanding it with reliably sourced entries. See also: List of file formats (alphabetical) This is a list of file formats… …   Wikipedia

  • Dietary fiber — Dietary fiber, dietary fibre, or sometimes roughage is the indigestible portion of plant foods having two main components: soluble (prebiotic, viscous) fiber that is readily fermented in the colon into gases and physiologically active byproducts …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”