Search

Your search keyword '"Fonseca, Maris V."' showing total 4 results
Start Over Author "Fonseca, Maris V." Journal journal of biological chemistry
4 results on '"Fonseca, Maris V."'

3. The ATP:Co(I)rrinoid Adenosyltransferase (CobA) Enzyme ofSalmonella entericaRequires the 2′-OH Group of ATP for Function and Yields Inorganic Triphosphate as Its Reaction Byproduct*

Author

Fonseca, Maris V., Buan, Nicole R., Horswill, Alexander R., Rayment, Ivan, and Escalante-Semerena, Jorge C.

Abstract

The specificity of the ATP:corrinoid adenosyltransferase (CobA) enzyme of Salmonella entericaserovar Typhimurium LT2 for its nucleotide substrate was tested using ATP analogs and alternative nucleotide donors. The enzyme showed broad specificity for the nucleotide base and required the 2′-OH group of the ribosyl moiety of ATP for activity. 31P NMR spectroscopy was used to identify inorganic triphosphate (PPPi) as the byproduct of the reaction catalyzed by the CobA enzyme. Cleavage of triphosphate into pyrophosphate and orthophosphate did not occur, indicating that triphosphate cleavage was not required for release of the adenosylcorrinoid product. Triphosphate was a strong inhibitor of the reaction, with 85% of CobA activity lost when the ATP/PPPiratio present in the reaction mixture was 1:2.5.

Published
2002
Full Text
View/download PDF

4. The ATP:Co(I)rrinoid adenosyltransferase (CobA) enzyme of Salmonella enterica requires the 2'-OH group of ATP for function and yields inorganic triphosphate as its reaction byproduct.

Author

Fonseca MV, Buan NR, Horswill AR, Rayment I, and Escalante-Semerena JC

Subjects
Adenosine Triphosphate metabolism, Binding Sites, Catalysis, Dose-Response Relationship, Drug, Magnetic Resonance Spectroscopy, Models, Chemical, Models, Molecular, Protein Binding, Substrate Specificity, Adenosine Triphosphate physiology, Alkyl and Aryl Transferases metabolism, Alkyl and Aryl Transferases physiology, Bacterial Proteins, Salmonella enterica enzymology
Abstract

The specificity of the ATP:corrinoid adenosyltransferase (CobA) enzyme of Salmonella enterica serovar Typhimurium LT2 for its nucleotide substrate was tested using ATP analogs and alternative nucleotide donors. The enzyme showed broad specificity for the nucleotide base and required the 2'-OH group of the ribosyl moiety of ATP for activity. (31)P NMR spectroscopy was used to identify inorganic triphosphate (PPP(i)) as the byproduct of the reaction catalyzed by the CobA enzyme. Cleavage of triphosphate into pyrophosphate and orthophosphate did not occur, indicating that triphosphate cleavage was not required for release of the adenosylcorrinoid product. Triphosphate was a strong inhibitor of the reaction, with 85% of CobA activity lost when the ATP/PPP(i) ratio present in the reaction mixture was 1:2.5.

Published
2002
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results