The Crystal Structure of 1-D-myo-Inosityl 2-Acetamido-2-deoxy-α-D-glucopyranoside Deacetylase (MshB) from Mycobacterium tuberculosis Reveals a Zinc Hydrolase with a Lactate Dehydrogenase Fold*

@article{Maynes2003TheCS,
  title={The Crystal Structure of 1-D-myo-Inosityl 2-Acetamido-2-deoxy-$\alpha$-D-glucopyranoside Deacetylase (MshB) from Mycobacterium tuberculosis Reveals a Zinc Hydrolase with a Lactate Dehydrogenase Fold*},
  author={J. Maynes and C. Garen and M. Cherney and G. Newton and D. Arad and Y. Av-Gay and R. C. Fahey and M. James},
  journal={Journal of Biological Chemistry},
  year={2003},
  volume={278},
  pages={47166 - 47170}
}
Mycothiol (1-d-myo-inosityl 2-(N-acetyl-l-cysteinyl)amido-2-deoxy-α-d-glucopyranoside, MSH or AcCys-GlcN-inositol (Ins)) is the major reducing agent in actinomycetes, including Mycobacterium tuberculosis. The biosynthesis of MSH involves a deacetylase that removes the acetyl group from the precursor GlcNAc-Ins to yield GlcN-Ins. The deacetylase (MshB) corresponds to Rv1170 of M. tuberculosis with a molecular mass of 33,400 Da. MshB is a Zn2+ metalloprotein, and the deacetylase activity is… Expand
Purification and characterization of Mycobacterium tuberculosis 1D-myo-inosityl-2-acetamido-2-deoxy-alpha-D-glucopyranoside deacetylase, MshB, a mycothiol biosynthetic enzyme.
Mycothiol (MSH, AcCys-GlcN-Ins) is the major low molecular weight thiol in actinomycetes and is essential for growth of Mycobacterium tuberculosis. MshB, the GlcNAc-Ins deacetylase, is a key enzymeExpand
The Activity and Cofactor Preferences of N-Acetyl-1-d-myo-inosityl-2-amino-2-deoxy-α-d-glucopyranoside Deacetylase (MshB) Change Depending on Environmental Conditions*
TLDR
The results indicate that the cofactor bound to MshB under biological conditions is dependent on environmental conditions, suggesting that MShB may be a cambialistic metallohydrolase that contains a dynamic cofactor. Expand
Molecular Determinants of N-Acetylglucosamine Recognition and Turnover by N-Acetyl-1-D-myo-inosityl-2-amino-2-deoxy-α-D-glucopyranoside Deacetylase (MshB).
TLDR
Results from these studies indicate that MshB is unable to catalyze the turnover of GlcNAc upon loss of the Arg68 or Asp95 side chains, consistent with the proposal that these side chains make critical hydrogen bonding interactions with substrate. Expand
Examination of Mechanism of N-Acetyl-1-d-myo-inosityl-2-amino-2-deoxy-α-d-glucopyranoside Deacetylase (MshB) Reveals Unexpected Role for Dynamic Tyrosine*
TLDR
Key side chains identified in these studies can be targeted for inhibitor development as they suggest that MshB functions through a general acid-base pair mechanism with the side chain of Asp-15 functioning as the general base catalyst and His-144 serving as thegeneral acid catalyst, whereas the side chains of Tyr-142 probably assists in polarizing substrate/stabilizing the oxyanion intermediate. Expand
A new crystal form of MshB from Mycobacterium tuberculosis with glycerol and acetate in the active site suggests the catalytic mechanism.
TLDR
The configuration of Tyr142 differs from that observed previously in crystal structures of MshB and its location provides direct structural support for recently published biochemical and mutational studies suggesting that this residue is involved in a conformational change on substrate binding and contributes to the oxyanion hole that stabilizes the tetrahedral intermediate. Expand
Automated docking studies provide insights into molecular determinants of ligand recognition by N-acetyl-1-D-myo-inosityl-2-amino-2-deoxy-α-D-glucopyranoside deacetylase (MshB).
TLDR
Results from these studies offer insights into molecular recognition by MshB via identification of side chains and dynamic loops that may play roles in ligand binding and suggest that a hydrophobic cavity adjacent to the active site may be one important determinant of MShB substrate specificity. Expand
An enzyme-initiated Smiles rearrangement enables the development of an assay of MshB, the GlcNAc-Ins deacetylase of mycothiol biosynthesis.
TLDR
This study demonstrates that structural analogues of GlcNAc-Ins in which the inosityl moiety is replaced by a chromophore were synthesized and evaluated as alternate substrates of MshB, with the goal of identifying a compound that would be useful in high-throughput assays of the enzyme. Expand
Biochemical studies of inositol N-acetylglucosaminyltransferase involved in mycothiol biosynthesis in Corynebacterium diphtheria.
TLDR
In this work, the MshA from Corynebacterium diphtheria was expressed, purified, and studied in detail, and its reaction kinetics with UDP-GlcNAc and 1L-Ins-1-P as substrates were characterized, while site-directed mutagenesis of CdMshA disclosed that its amino acid residues N28, K81 and R157 were essential for its enzymatic activity. Expand
Conjugates of plumbagin and phenyl-2-amino-1-thioglucoside inhibit MshB, a deacetylase involved in the biosynthesis of mycothiol.
N-Acetylglucosaminylinositol (GlcNAc-Ins)-deacetylase (MshB) and mycothiol-S-conjugate amidase (Mca), structurally related amidases present in mycobacteria and other Actinomycetes, are involved inExpand
Biochemistry of the Initial Steps of Mycothiol Biosynthesis*
TLDR
The biochemical pathway of mycothiol biosynthesis is now fully elucidated and the presence of a myo-inositol transporter and a kinase that generates 1l-myo- inositol 1-phosphate is demonstrated. Expand
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References

SHOWING 1-10 OF 32 REFERENCES
N-Acetyl-1-d-myo-Inosityl-2-Amino-2-Deoxy-α-d-Glucopyranoside Deacetylase (MshB) Is a Key Enzyme in Mycothiol Biosynthesis
ABSTRACT Mycothiol is a novel thiol produced only by actinomycetes and is the major low-molecular-weight thiol in mycobacteria. Mycothiol was previously shown to be synthesized fromExpand
ATP-dependent L-cysteine:1D-myo-inosityl 2-amino-2-deoxy-alpha-D-glucopyranoside ligase, mycothiol biosynthesis enzyme MshC, is related to class I cysteinyl-tRNA synthetases.
TLDR
The results indicate that cysS2 is actually the mshC gene encoding ATP-dependent Cys:GlcN-Ins ligase, which is the major low molecular weight thiol in mycobacteria. Expand
A novel mycothiol-dependent detoxification pathway in mycobacteria involving mycothiol S-conjugate amidase.
TLDR
The results indicate that mycothiol and myCothiol S-conjugate amidase play an important role in the detoxification of alkylating agents and antibiotics. Expand
Characterization of Mycobacterium smegmatis mutants defective in 1-d-myo-inosityl-2-amino-2-deoxy-alpha-d-glucopyranoside and mycothiol biosynthesis.
TLDR
The results indicate that MSH and GlcN-Ins are not essential for in vitro survival of mycobacteria but may play significant roles in determining the sensitivity of myCobacteria to environmental toxins. Expand
Identification of the mycothiol synthase gene (mshD) encoding the acetyltransferase producing mycothiol in actinomycetes
TLDR
The isolation and characterization of a Tn5 transposon mutant of Mycobacterium smegmatis that is blocked in the production of mycothiol and accumulates its precursor, 1D-myo-inosityl 2-L-cysteinylamido-2-deoxy-α-D-glucopyranoside (Cys-GlcN-Ins). Expand
The metabolism of nitrosothiols in the Mycobacteria: identification and characterization of S-nitrosomycothiol reductase.
TLDR
A possible route in vivo for the dissimilation of S-nitrosoglutathione is suggested and the mycothiol-dependent formaldehyde dehydrogenase from M. smegmatis was purified by a combination of Ni2+-IMAC (immobilized metal ion affinity chromatography), hydrophobic interaction, anion-exchange and affinity Chromatography. Expand
Cloning of Trypanosoma brucei and Leishmania major Genes Encoding the GlcNAc-Phosphatidylinositol De-N-acetylase of Glycosylphosphatidylinositol Biosynthesis That Is Essential to the African Sleeping Sickness Parasite*
TLDR
TbGPI12 is an essential gene for the tsetse-transmitted parasite that causes Nagana in cattle and African sleeping sickness in humans, and validates GlcNAc-PI de-N-acetylase as a potential drug target against these diseases. Expand
Mycothiol-Deficient Mycobacterium smegmatis Mutants Are Hypersensitive to Alkylating Agents, Free Radicals, and Antibiotics
TLDR
The results demonstrate that there is a direct correlation between MSH depletion and enhanced sensitivity to toxins and antibiotics and that a single amino acid substitution (L205P) is responsible for reduced MSH production and its associated phenotype. Expand
Distribution of thiols in microorganisms: mycothiol is a major thiol in most actinomycetes
TLDR
The results, which indicate that MSH production is restricted to the actinomycetes, could have significant implications for the detection and treatment of infections with actinomers, especially those caused by mycobacteria. Expand
Association of mycothiol with protection of Mycobacterium tuberculosis from toxic oxidants and antibiotics
TLDR
It is established that the Rv1170 gene encodes for the major GlcNAc‐Ins deacetylase activity (termed MshB) in the MSH biosynthetic pathway of M. tuberculosis, indicating that MSH contributes to the protection ofM. Expand
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