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Rv2131c from Mycobacterium tuberculosis Is a CysQ 3′-Phosphoadenosine-5′-phosphatase

[Image: see text] Mycobacterium tuberculosis (Mtb) produces a number of sulfur-containing metabolites that contribute to its pathogenesis and ability to survive in the host. These metabolites are products of the sulfate assimilation pathway. CysQ, a 3′-phosphoadenosine-5′-phosphatase, is considered...

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Autores principales: Hatzios, Stavroula K., Iavarone, Anthony T., Bertozzi, Carolyn R.
Formato: Texto
Lenguaje:English
Publicado: American Chemical Society 2008
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2711008/
https://www.ncbi.nlm.nih.gov/pubmed/18454554
http://dx.doi.org/10.1021/bi702453s
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author Hatzios, Stavroula K.
Iavarone, Anthony T.
Bertozzi, Carolyn R.
author_facet Hatzios, Stavroula K.
Iavarone, Anthony T.
Bertozzi, Carolyn R.
author_sort Hatzios, Stavroula K.
collection PubMed
description [Image: see text] Mycobacterium tuberculosis (Mtb) produces a number of sulfur-containing metabolites that contribute to its pathogenesis and ability to survive in the host. These metabolites are products of the sulfate assimilation pathway. CysQ, a 3′-phosphoadenosine-5′-phosphatase, is considered an important regulator of this pathway in plants, yeast, and other bacteria. By controlling the pools of 3′-phosphoadenosine 5′-phosphate (PAP) and 3′-phosphoadenosine 5′-phosphosulfate (PAPS), CysQ has the potential to modulate flux in the biosynthesis of essential sulfur-containing metabolites. Bioinformatic analysis of the Mtb genome suggests the presence of a CysQ homologue encoded by the gene Rv2131c. However, a recent biochemical study assigned the protein’s function as a class IV fructose-1,6-bisphosphatase. In the present study, we expressed Rv2131c heterologously and found that the protein dephosphorylates PAP in a magnesium-dependent manner, with optimal activity observed between pH 8.5 and pH 9.5 using 0.5 mM MgCl(2). A sensitive electrospray ionization mass spectrometry-based assay was used to extract the kinetic parameters for PAP, revealing a K(m) (8.1 ± 3.1 μM) and k(cat) (5.4 ± 1.1 s(−1)) comparable to those reported for other CysQ enzymes. The second-order rate constant for PAP was determined to be over 3 orders of magnitude greater than those determined for myo-inositol 1-phosphate (IMP) and fructose 1,6-bisphosphate (FBP), previously considered to be the primary substrates of this enzyme. Moreover, the ability of the Rv2131c-encoded enzyme to dephosphorylate PAP and PAPS in vivo was confirmed by functional complementation of an Escherichia coli ΔcysQ mutant. Taken together, these studies indicate that Rv2131c encodes a CysQ enzyme that may play a role in mycobacterial sulfur metabolism.
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spelling pubmed-27110082009-07-15 Rv2131c from Mycobacterium tuberculosis Is a CysQ 3′-Phosphoadenosine-5′-phosphatase Hatzios, Stavroula K. Iavarone, Anthony T. Bertozzi, Carolyn R. Biochemistry [Image: see text] Mycobacterium tuberculosis (Mtb) produces a number of sulfur-containing metabolites that contribute to its pathogenesis and ability to survive in the host. These metabolites are products of the sulfate assimilation pathway. CysQ, a 3′-phosphoadenosine-5′-phosphatase, is considered an important regulator of this pathway in plants, yeast, and other bacteria. By controlling the pools of 3′-phosphoadenosine 5′-phosphate (PAP) and 3′-phosphoadenosine 5′-phosphosulfate (PAPS), CysQ has the potential to modulate flux in the biosynthesis of essential sulfur-containing metabolites. Bioinformatic analysis of the Mtb genome suggests the presence of a CysQ homologue encoded by the gene Rv2131c. However, a recent biochemical study assigned the protein’s function as a class IV fructose-1,6-bisphosphatase. In the present study, we expressed Rv2131c heterologously and found that the protein dephosphorylates PAP in a magnesium-dependent manner, with optimal activity observed between pH 8.5 and pH 9.5 using 0.5 mM MgCl(2). A sensitive electrospray ionization mass spectrometry-based assay was used to extract the kinetic parameters for PAP, revealing a K(m) (8.1 ± 3.1 μM) and k(cat) (5.4 ± 1.1 s(−1)) comparable to those reported for other CysQ enzymes. The second-order rate constant for PAP was determined to be over 3 orders of magnitude greater than those determined for myo-inositol 1-phosphate (IMP) and fructose 1,6-bisphosphate (FBP), previously considered to be the primary substrates of this enzyme. Moreover, the ability of the Rv2131c-encoded enzyme to dephosphorylate PAP and PAPS in vivo was confirmed by functional complementation of an Escherichia coli ΔcysQ mutant. Taken together, these studies indicate that Rv2131c encodes a CysQ enzyme that may play a role in mycobacterial sulfur metabolism. American Chemical Society 2008-05-03 2008-05-27 /pmc/articles/PMC2711008/ /pubmed/18454554 http://dx.doi.org/10.1021/bi702453s Text en Copyright © 2008 American Chemical Society http://pubs.acs.org This is an open-access article distributed under the ACS AuthorChoice Terms & Conditions. Any use of this article, must conform to the terms of that license which are available at http://pubs.acs.org. 40.75
spellingShingle Hatzios, Stavroula K.
Iavarone, Anthony T.
Bertozzi, Carolyn R.
Rv2131c from Mycobacterium tuberculosis Is a CysQ 3′-Phosphoadenosine-5′-phosphatase
title Rv2131c from Mycobacterium tuberculosis Is a CysQ 3′-Phosphoadenosine-5′-phosphatase
title_full Rv2131c from Mycobacterium tuberculosis Is a CysQ 3′-Phosphoadenosine-5′-phosphatase
title_fullStr Rv2131c from Mycobacterium tuberculosis Is a CysQ 3′-Phosphoadenosine-5′-phosphatase
title_full_unstemmed Rv2131c from Mycobacterium tuberculosis Is a CysQ 3′-Phosphoadenosine-5′-phosphatase
title_short Rv2131c from Mycobacterium tuberculosis Is a CysQ 3′-Phosphoadenosine-5′-phosphatase
title_sort rv2131c from mycobacterium tuberculosis is a cysq 3′-phosphoadenosine-5′-phosphatase
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2711008/
https://www.ncbi.nlm.nih.gov/pubmed/18454554
http://dx.doi.org/10.1021/bi702453s
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