This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Errey, J. C.
Right arrow Articles by Blanchard, J. S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Errey, J. C.
Right arrow Articles by Blanchard, J. S.

 Previous Article  |  Next Article 

Journal of Bacteriology, May 2005, p. 3039-3044, Vol. 187, No. 9
0021-9193/05/$08.00+0     doi:10.1128/JB.187.9.3039-3044.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Functional Characterization of a Novel ArgA from Mycobacterium tuberculosis

James C. Errey and John S. Blanchard*

Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461

Received 30 November 2004/ Accepted 21 January 2005

The Mycobacterium tuberculosis gene Rv2747 encodes a novel 19-kDa ArgA that catalyzes the initial step in L-arginine biosynthesis, namely the conversion of L-glutamate to {alpha}-N-acetyl-L-glutamate. Initial velocity studies reveal that Rv2747 proceeds through a sequential kinetic mechanism, with Km values of 280 mM for L-glutamine and 150 µM for acetyl-coenzyme A and with a kcat value of 200 min–1. Initial velocity studies with L-glutamate showed that even at concentrations of 600 mM, saturation was not observed. Therefore, only a kcat/Km value of 125 M–1 min–1 can be calculated. Inhibition studies reveal that the enzyme is strongly regulated by L-arginine, the end product of the pathway (50% inhibitory concentration, 26 µM). The enzyme was completely inhibited by 500 µM arginine, with a Hill coefficient of 0.60, indicating negatively cooperative binding of L-arginine.

* Corresponding author. Mailing address: Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461. Phone (718) 430-3096. Fax: (718) 430-8565. E-mail: blanchar{at}aecom.yu.edu.

Journal of Bacteriology, May 2005, p. 3039-3044, Vol. 187, No. 9
0021-9193/05/$08.00+0     doi:10.1128/JB.187.9.3039-3044.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Min, L., Jin, Z., Caldovic, L., Morizono, H., Allewell, N. M., Tuchman, M., Shi, D. (2009). Mechanism of Allosteric Inhibition of N-Acetyl-L-glutamate Synthase by L-Arginine. J. Biol. Chem. 284: 4873-4880 [Abstract] [Full Text]  
  • Shi, D., Sagar, V., Jin, Z., Yu, X., Caldovic, L., Morizono, H., Allewell, N. M., Tuchman, M. (2008). The Crystal Structure of N-Acetyl-L-glutamate Synthase from Neisseria gonorrhoeae Provides Insights into Mechanisms of Catalysis and Regulation. J. Biol. Chem. 283: 7176-7184 [Abstract] [Full Text]  
  • Xu, Y., Labedan, B., Glansdorff, N. (2007). Surprising Arginine Biosynthesis: a Reappraisal of the Enzymology and Evolution of the Pathway in Microorganisms. Microbiol. Mol. Biol. Rev. 71: 36-47 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»