scholarly journals Active Site Loop Dynamics of a Class IIa Fructose 1,6-Bisphosphate Aldolase from Mycobacterium tuberculosis

Biochemistry ◽  
2013 ◽  
Vol 52 (5) ◽  
pp. 912-925 ◽  
Author(s):  
Scott D. Pegan ◽  
Kamolchanok Rukseree ◽  
Glenn C. Capodagli ◽  
Erica A. Baker ◽  
Olga Krasnykh ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Active Site ◽  
Loop Dynamics ◽  
Fructose 1,6 Bisphosphate

Crystal structure of hexanoyl-CoA bound to β-ketoacyl reductase FabG4 of Mycobacterium tuberculosis

2013 ◽  
Vol 450 (1) ◽  
pp. 127-139 ◽  
Author(s):  
Debajyoti Dutta ◽  
Sudipta Bhattacharyya ◽  
Amlan Roychowdhury ◽  
Rupam Biswas ◽  
Amit Kumar Das
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Active Site ◽  
Ternary Complex ◽  
Catalytic Mechanism ◽  
Acyl Carrier Protein ◽  
Structural Data ◽  
Acid Synthesis ◽  
Binary Complex ◽  
C Terminus ◽  
Covalently Linked

FabGs, or β-oxoacyl reductases, are involved in fatty acid synthesis. The reaction entails NADPH/NADH-mediated conversion of β-oxoacyl-ACP (acyl-carrier protein) into β-hydroxyacyl-ACP. HMwFabGs (high-molecular-weight FabG) form a phylogenetically separate group of FabG enzymes. FabG4, an HMwFabG from Mycobacterium tuberculosis, contains two distinct domains, an N-terminal ‘flavodoxintype’ domain and a C-terminal oxoreductase domain. The catalytically active C-terminal domain utilizes NADH to reduce β-oxoacyl-CoA to β-hydroxyacyl-CoA. In the present study the crystal structures of the FabG4–NADH binary complex and the FabG4–NAD+–hexanoyl-CoA ternary complex have been determined to understand the substrate specificity and catalytic mechanism of FabG4. This is the first report to demonstrate how FabG4 interacts with its coenzyme NADH and hexanoyl-CoA that mimics an elongating fattyacyl chain covalently linked with CoA. Structural analysis shows that the binding of hexanoyl-CoA within the active site cavity of FabG significantly differs from that of the C16 fattyacyl substrate bound to mycobacterial FabI [InhA (enoyl-ACP reductase)]. The ternary complex reveals that both loop I and loop II interact with the phosphopantetheine moiety of CoA or ACP to align the covalently linked fattyacyl substrate near the active site. Structural data ACP inhibition studies indicate that FabG4 can accept both CoA- and ACP-based fattyacyl substrates. We have also shown that in the FabG4 dimer Arg146 and Arg445 of one monomer interact with the C-terminus of the second monomer to play pivotal role in substrate association and catalysis.

Structure, interactions and action of Mycobacterium tuberculosis 3-hydroxyisobutyric acid dehydrogenase

2018 ◽  
Vol 475 (15) ◽  
pp. 2457-2471 ◽  
Author(s):  
Rajapiramuthu Srikalaivani ◽  
Amrita Singh ◽  
Mamannamana Vijayan ◽  
Avadhesha Surolia
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Active Site ◽  
Mutational Analysis ◽  
Gel Filtration ◽  
Ph Optimum ◽  
Native Page ◽  
Acid Dehydrogenase ◽  
Binary Complexes ◽  
Solution Studies ◽  
Hydroxyisobutyric Acid

Biochemical and crystallographic studies on Mycobacterium tuberculosis 3-hydroxyisobutyric acid dehydrogenase (MtHIBADH), a member of the 3-hydroxyacid dehydrogenase superfamily, have been carried out. Gel filtration and blue native PAGE of MtHIBADH show that the enzyme is a dimer. The enzyme preferentially uses NAD+ as the cofactor and is specific to S-hydroxyisobutyric acid (HIBA). It can also use R-HIBA, l-serine and 3-hydroxypropanoic acid (3-HP) as substrates, but with much less efficiency. The pH optimum for activity is ∼11. Structures of the native enzyme, the holoenzyme, binary complexes with NAD+, S-HIBA, R-HIBA, l-serine and 3-HP and ternary complexes involving the substrates and NAD+ have been determined. None of the already known structures of HIBADH contain a substrate molecule at the binding site. The structures reported here provide for the first time, among other things, a clear indication of the location and interactions of the substrates at the active site. They also define the entrance of the substrates to the active site region. The structures provide information on the role of specific residues at the active site and the entrance. The results obtained from crystal structures are consistent with solution studies including mutational analysis. They lead to the proposal of a plausible mechanism of the action of the enzyme.

Relationship of Catalysis and Active Site Loop Dynamics in the (βα)8-Barrel Enzyme Indole-3-glycerol Phosphate Synthase

Biochemistry ◽  
2018 ◽  
Vol 57 (23) ◽  
pp. 3265-3277 ◽  
Author(s):  
Sandra Schlee ◽  
Thomas Klein ◽  
Magdalena Schumacher ◽  
Julian Nazet ◽  
Rainer Merkl ◽  
...  
Keyword(s):  
Active Site ◽  
Glycerol Phosphate ◽  
Loop Dynamics ◽  
Relationship Of ◽  
Phosphate Synthase

scholarly journals Design and Synthesis of Various 5′-Deoxy-5′-(4-Substituted-1,2,3-Triazol-1-yl)-Uridine Analogues as Inhibitors of Mycobacterium tuberculosis Mur Ligases

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4953
Author(s):  
Vincent Hervin ◽  
Ritu Arora ◽  
Jyoti Rani ◽  
Srinivasan Ramchandran ◽  
Urmi Bajpai ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Molecular Docking ◽  
Active Site ◽  
Inhibitory Effect ◽  
Natural Substrate ◽  
Screening Assay ◽  
One Pot ◽  
Peptidoglycan Biosynthesis ◽  
Design And Synthesis ◽  
Structure Activity

The synthesis of hitherto unknown 5′-deoxy-5′-(4-substituted-1,2,3-triazol-1-yl)-uridine and its evaluation, through an one-pot screening assay, against MurA-F enzymes involved in Mycobacterium tuberculosis (Mtb), are described. Starting from UDP-N-acetylmuramic acid (UDP-MurNAc), the natural substrate involved in the peptidoglycan biosynthesis, our strategy was to substitute the diphosphate group of UDP-MurNAc by a 1,2,3-triazolo spacer under copper-catalyzed azide-alkyne cycloaddition conditions. The structure-activity relationship was discussed and among the 23 novel compounds developed, N-acetylglucosamine analogues 11c and 11e emerged as the best inhibitors against the Mtb MurA-F enzymes reconstruction pathway with an inhibitory effect of 56% and 50%, respectively, at 100 μM. Both compounds are selective inhibitors of Mtb MurE, the molecular docking and molecular dynamic simulation suggesting that 11c and 11e are occupying the active site of Mtb MurE ligase.

scholarly journals Crystal Structure of African Swine Fever Virus dUTPase Reveals a Potential Drug Target

mBio ◽  
2019 ◽  
Vol 10 (5) ◽  
Author(s):  
Changyao Li ◽  
Yan Chai ◽  
Hao Song ◽  
Changjiang Weng ◽  
Jianxun Qi ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Mycobacterium Tuberculosis ◽  
High Resolution ◽  
Drug Design ◽  
Active Site ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Potential Drug ◽  
Content Type

ABSTRACT E165R, a highly specific dUTP nucleotidohydrolase (dUTPase) encoded by the African swine fever virus (ASFV) genome, is required for productive replication of ASFV in swine macrophages. Here, we solved the high-resolution crystal structures of E165R in its apo state and in complex with its product dUMP. Structural analysis explicitly defined the architecture of the active site of the enzyme as well as the interaction between the active site and the dUMP ligand. By comparing the ASFV E165R structure with dUTPase structures from other species, we found that the active site of E165R is highly similar to those of dUTPases from Mycobacterium tuberculosis and Plasmodium falciparum, against which small-molecule chemicals have been developed, which could be the potential drug or lead compound candidates for ASFV. Our results provide important basis for anti-ASFV drug design by targeting E165R. IMPORTANCE African swine fever virus (ASFV), an Asfivirus affecting pigs and wild boars with up to 100% case fatality rate, is currently rampaging throughout China and some other countries in Asia. There is an urgent need to develop therapeutic and preventive reagents against the virus. Our crystallographic and biochemical studies reveal that ASFV E165R is a member of trimeric dUTP nucleotidohydrolase (dUTPase) family that catalyzes the hydrolysis of dUTP into dUMP. Our apo-E165R and E165R-dUMP structures reveal the constitutive residues and the configuration of the active center of this enzyme in rich detail and give evidence that the active center of E165R is very similar to that of dUTPases from Plasmodium falciparum and Mycobacterium tuberculosis, which have already been used as targets for designing drugs. Therefore, our high-resolution structures of E165R provide useful structural information for chemotherapeutic drug design.

scholarly journals Biochemical and Structural Characterization of the Secreted Chorismate Mutase (Rv1885c) from Mycobacterium tuberculosis H37Rv: an *AroQ Enzyme Not Regulated by the Aromatic Amino Acids

2006 ◽  
Vol 188 (24) ◽  
pp. 8638-8648 ◽  
Author(s):  
Sook-Kyung Kim ◽  
Sathyavelu K. Reddy ◽  
Bryant C. Nelson ◽  
Gregory B. Vasquez ◽  
Andrew Davis ◽  
...  
Keyword(s):  
Amino Acids ◽  
Mycobacterium Tuberculosis ◽  
Active Site ◽  
Signal Sequence ◽  
Aromatic Amino Acids ◽  
Helical Structure ◽  
Data Bank ◽  
Chorismate Mutase ◽  
Site Directed Mutagenesis ◽  
Single Chain

ABSTRACT The gene Rv1885c from the genome of Mycobacterium tuberculosis H37Rv encodes a monofunctional and secreted chorismate mutase (*MtCM) with a 33-amino-acid cleavable signal sequence; hence, it belongs to the *AroQ class of chorismate mutases. Consistent with the heterologously expressed *MtCM having periplasmic destination in Escherichia coli and the absence of a discrete periplasmic compartment in M. tuberculosis, we show here that *MtCM secretes into the culture filtrate of M. tuberculosis. *MtCM functions as a homodimer and exhibits a dimeric state of the protein at a concentration as low as 5 nM. *MtCM exhibits simple Michaelis-Menten kinetics with a Km of 0.5 ± 0.05 mM and a k cat of 60 s−1 per active site (at 37°C and pH 7.5). The crystal structure of *MtCM has been determined at 1.7 Å resolution (Protein Data Bank identifier 2F6L). The protein has an all alpha-helical structure, and the active site is formed within a single chain without any contribution from the second chain in the dimer. Analysis of the structure shows a novel fold topology for the protein with a topologically rearranged helix containing Arg134. We provide evidence by site-directed mutagenesis that the residues Arg49, Lys60, Arg72, Thr105, Glu109, and Arg134 constitute the catalytic site; the numbering of the residues includes the signal sequence. Our investigation on the effect of phenylalanine, tyrosine, and tryptophan on *MtCM shows that *MtCM is not regulated by the aromatic amino acids. Consistent with this observation, the X-ray structure of *MtCM does not have an allosteric regulatory site.

scholarly journals Reconstruction of Mycobacterial Dehalogenase Rv2579 by Cumulative Mutagenesis of Haloalkane Dehalogenase LinB

2003 ◽  
Vol 69 (4) ◽  
pp. 2349-2355 ◽  
Author(s):  
Yuji Nagata ◽  
Zbyněk Prokop ◽  
Soňa Marvanová ◽  
Jana Sýkorová ◽  
Marta Monincová ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Mycobacterium Tuberculosis ◽  
Amino Acid ◽  
Active Site ◽  
Homology Model ◽  
Protein Family ◽  
Sphingomonas Paucimobilis ◽  
Amino Acid Residues ◽  
Haloalkane Dehalogenase

ABSTRACT The homology model of protein Rv2579 from Mycobacterium tuberculosis H37Rv was compared with the crystal structure of haloalkane dehalogenase LinB from Sphingomonas paucimobilis UT26, and this analysis revealed that 6 of 19 amino acid residues which form an active site and entrance tunnel are different in LinB and Rv2579. To characterize the effect of replacement of these six amino acid residues, mutations were introduced cumulatively into the six amino acid residues of LinB. The sixfold mutant, which was supposed to have the active site of Rv2579, exhibited haloalkane dehalogenase activity with the haloalkanes tested, confirming that Rv2579 is a member of the haloalkane dehalogenase protein family.

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