scholarly journals A core catalytic domain of the TyrA protein family: arogenate dehydrogenase from Synechocystis

2004 ◽  
Vol 382 (1) ◽  
pp. 279-291 ◽  
Author(s):  
Carol A. BONNER ◽  
Roy A. JENSEN ◽  
John E. GANDER ◽  
Nemat O. KEYHANI
Keyword(s):  
Catalytic Domain ◽  
Random Order ◽  
Protein Family ◽  
Catalytic Core ◽  
Core Domain ◽  
Apparent Homogeneity ◽  
High Preference ◽  
Competitive Inhibitors ◽  
Comparative Enzymology ◽  
Arogenate Dehydrogenase

The TyrA protein family includes prephenate dehydrogenases, cyclohexadienyl dehydrogenases and TyrAas (arogenate dehydrogenases). tyrAa from Synechocystis sp. PCC 6803, encoding a 30 kDa TyrAa protein, was cloned into an overexpression vector in Escherichia coli. TyrAa was then purified to apparent homogeneity and characterized. This protein is a model structure for a catalytic core domain in the TyrA superfamily, uncomplicated by allosteric or fused domains. Competitive inhibitors acting at the catalytic core of TyrA proteins are analogues of any accepted cyclohexadienyl substrate. The homodimeric enzyme was specific for L-arogenate (Km=331 μM) and NADP+ (Km=38 μM), being unable to substitute prephenate or NAD+ respectively. L-Tyrosine was a potent inhibitor of the enzyme (Ki=70 μM). NADPH had no detectable ability to inhibit the reaction. Although the mechanism is probably steady-state random order, properties of 2′,5′-ADP as an inhibitor suggest a high preference for L-arogenate binding first. Comparative enzymology established that both of the arogenate-pathway enzymes, prephenate aminotransferase and TyrAa, were present in many diverse cyanobacteria and in a variety of eukaryotic red and green algae.

scholarly journals Peptides Derived from the Reverse Transcriptase of Human Immunodeficiency Virus Type 1 as Novel Inhibitors of the Viral Integrase

2005 ◽  
Vol 280 (23) ◽  
pp. 21987-21996 ◽  
Author(s):  
Iris Oz Gleenberg ◽  
Orna Avidan ◽  
Yehuda Goldgur ◽  
Alon Herschhorn ◽  
Amnon Hizi
Keyword(s):  
Reverse Transcriptase ◽  
Catalytic Domain ◽  
Three Dimensional ◽  
Specific Protein ◽  
Strand Transfer ◽  
Catalytic Core ◽  
Core Domain ◽  
Inhibitory Peptides ◽  
Hiv 1

Recent studies have shown that the integrase (IN) of HIV-1 is inhibited in vitro by HIV-1 reverse transcriptase (RT). We further investigated the specific protein sequences of RT that were involved in this inhibition by screening a complete library of RT-derived peptides for their inhibition of IN activities. Two 20-residue peptides, peptide 4286, derived from the RT DNA polymerase domain, and the one designated 4321, from the RT ribonuclease H domain, inhibit the enzymatic activities of IN in vitro. The former peptide inhibits all three IN-associated activities (3′-end processing, strand transfer, and disintegration), whereas the latter one inhibits primarily the first two functions. We showed the importance of the sequences and peptide length for the effective inhibition of IN activities. Binding assays of the peptides to IN (with no DNA substrate present) indicated that the two inhibitory peptides (as well as several non-inhibitory peptides) interact directly with IN. Moreover, the isolated catalytic core domain of IN also interacted directly with the two inhibitory peptides. Nevertheless, only peptide 4286 can inhibit the disintegration activity associated with the IN core domain, because this activity is the only one exhibited by this domain. This result was expected from the lack of inhibition of disintegration of full-length IN by peptide 4321. The data and the three-dimensional models presented suggested that the inhibition resulted from steric hindrance of the catalytic domain of IN. This information can substantially facilitate the development of novel drugs against HIV INs and thus contribute to the fight against AIDS.

scholarly journals Purification, crystallization and preliminary crystallographic analysis of the catalytic domain of the extracellular cellulase CBHI fromTrichoderma harzianum

2010 ◽  
Vol 66 (9) ◽  
pp. 1041-1044 ◽  
Author(s):  
Francieli Colussi ◽  
Larissa C. Textor ◽  
Viviane Serpa ◽  
Roberto Nobuyuki Maeda ◽  
Nei Pereira ◽  
...  
Keyword(s):  
Microcrystalline Cellulose ◽  
Catalytic Domain ◽  
Crystallographic Analysis ◽  
Cellulolytic Activity ◽  
X Ray Diffraction ◽  
Cellobiohydrolase I ◽  
Data Set ◽  
Catalytic Core ◽  
Core Domain ◽  
Hydrolysis Of

The filamentous fungusTrichoderma harzianumhas a considerable cellulolytic activity that is mediated by a complex of enzymes which are essential for the hydrolysis of microcrystalline cellulose. These enzymes were produced by the induction ofT. harzianumwith microcrystalline cellulose (Avicel) under submerged fermentation in a bioreactor. The catalytic core domain (CCD) of cellobiohydrolase I (CBHI) was purified from the extracellular extracts and submitted to robotic crystallization. Diffraction-quality CBHI CCD crystals were grown and an X-ray diffraction data set was collected under cryogenic conditions using a synchrotron-radiation source.

scholarly journals Targeting neddylation E2s: a novel therapeutic strategy in cancer

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yi-Chao Zheng ◽  
Yan-Jia Guo ◽  
Bo Wang ◽  
Chong Wang ◽  
M. A. A. Mamun ◽  
...  
Keyword(s):  
Posttranslational Modification ◽  
Therapeutic Strategy ◽  
Neural Precursor Cell ◽  
Catalytic Core Domain ◽  
Catalytic Core ◽  
Core Domain ◽  
E3 Ligases ◽  
Ubiquitin Conjugating Enzyme ◽  
E2 Enzymes ◽  
Conjugating Enzyme

AbstractUbiquitin-conjugating enzyme E2 M (UBE2M) and ubiquitin-conjugating enzyme E2 F (UBE2F) are the two NEDD8-conjugating enzymes of the neddylation pathway that take part in posttranslational modification and change the activity of target proteins. The activity of E2 enzymes requires both a 26-residue N-terminal docking peptide and a conserved E2 catalytic core domain, which is the basis for the transfer of neural precursor cell-expressed developmentally downregulated 8 (NEDD8). By recruiting E3 ligases and targeting cullin and non-cullin substrates, UBE2M and UBE2F play diverse biological roles. Currently, there are several inhibitors that target the UBE2M-defective in cullin neddylation protein 1 (DCN1) interaction to treat cancer. As described above, this review provides insights into the mechanism of UBE2M and UBE2F and emphasizes these two E2 enzymes as appealing therapeutic targets for the treatment of cancers.

scholarly journals Crystal Structure ofDeinococcus radioduransRecQ Helicase Catalytic Core Domain: The Interdomain Flexibility

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Sheng-Chia Chen ◽  
Chi-Hung Huang ◽  
Chia Shin Yang ◽  
Tzong-Der Way ◽  
Ming-Chung Chang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Deinococcus Radiodurans ◽  
Domain Architecture ◽  
Genome Integrity ◽  
Catalytic Core Domain ◽  
Catalytic Core ◽  
Core Domain ◽  
Winged Helix ◽  
Dna Helicases ◽  
E Coli

RecQ DNA helicases are key enzymes in the maintenance of genome integrity, and they have functions in DNA replication, recombination, and repair. In contrast to most RecQs, RecQ fromDeinococcus radiodurans(DrRecQ) possesses an unusual domain architecture that is crucial for its remarkable ability to repair DNA. Here, we determined the crystal structures of the DrRecQ helicase catalytic core and its ADP-bound form, revealing interdomain flexibility in its first RecA-like and winged-helix (WH) domains. Additionally, the WH domain of DrRecQ is positioned in a different orientation from that of theE. coliRecQ (EcRecQ). These results suggest that the orientation of the protein during DNA-binding is significantly different when comparing DrRecQ and EcRecQ.

scholarly journals The Effect of Geometrical Isomerism of 3,5-Dicaffeoylquinic Acid on Its Binding Affinity to HIV-Integrase Enzyme: A Molecular Docking Study

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Mpho M. Makola ◽  
Ian A. Dubery ◽  
Gerrit Koorsen ◽  
Paul A. Steenkamp ◽  
Mwadham M. Kabanda ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Density Functional ◽  
Catalytic Domain ◽  
Synergistic Activity ◽  
Hiv Integrase ◽  
Molecular Docking Study ◽  
Geometrical Isomers ◽  
Catalytic Core ◽  
Dicaffeoylquinic Acid ◽  
Hiv 1

A potent plant-derived HIV-1 inhibitor, 3,5-dicaffeoylquinic acid (diCQA), has been shown to undergo isomerisation upon UV exposure where the naturally occurring3trans,5trans-diCQA isomer gives rise to the3cis,5trans-diCQA,3trans,5cis-diCQA, and3cis,5cis-diCQA isomers. In this study, inhibition of HIV-1 INT by UV-induced isomers was investigated using molecular docking methods. Here, density functional theory (DFT) models were used for geometry optimization of the 3,5-diCQA isomers. The YASARA and Autodock VINA software packages were then used to determine the binding interactions between the HIV-1 INT catalytic domain and the 3,5-diCQA isomers and the Discovery Studio suite was used to visualise the interactions between the isomers and the protein. The geometrical isomers of 3,5-diCQA were all found to bind to the catalytic core domain of the INT enzyme. Moreover, thecisgeometrical isomers were found to interact with the metal cofactor of HIV-1INT, a phenomenon which has been linked to antiviral potency. Furthermore, the3trans,5cis-diCQA isomer was also found to interact with both LYS156 and LYS159 which are important residues for viral DNA integration. The differences in binding modes of these naturally coexisting isomers may allow wider synergistic activity which may be beneficial in comparison to the activities of each individual isomer.

The crystal structure of the catalytic core domain of endoglucanase I from Trichoderma reesei at 3.6 Å resolution, and a comparison with related enzymes 1 1Edited by K.Nagai

1997 ◽  
Vol 272 (3) ◽  
pp. 383-397 ◽  
Author(s):  
Gerard J Kleywegt ◽  
Jin-Yu Zou ◽  
Christina Divne ◽  
Gideon J Davies ◽  
Irmgard Sinning ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Trichoderma Reesei ◽  
Catalytic Core Domain ◽  
Catalytic Core ◽  
Core Domain ◽  
Endoglucanase I

scholarly journals Structural identification of the myo-inositol 1,4,5-trisphosphate-binding domain in rat brain inositol 1,4,5-trisphosphate 3-kinase

1997 ◽  
Vol 326 (1) ◽  
pp. 221-225 ◽  
Author(s):  
Shinji TOGASHI ◽  
Kazunaga TAKAZAWA ◽  
Toyoshi ENDO ◽  
Christophe ERNEUX ◽  
Toshimasa ONAYA
Keyword(s):  
Amino Acids ◽  
Rat Brain ◽  
Kinase Activity ◽  
Catalytic Domain ◽  
Site Directed Mutagenesis ◽  
Wild Type ◽  
Wild Type Enzyme ◽  
Apparent Homogeneity ◽  
Inositol 1,4,5 Trisphosphate ◽  
Charged Amino Acid Residue

A series of key amino acids involved in Ins(1,4,5)P3 (InsP3) binding and catalytic activity of rat brain InsP3 3-kinase has been identified. The catalytic domain is at the C-terminal end and restricted to a maximum of 275 amino acids [Takazawa and Erneux (1991) Biochem. J. 280, 125–129]. In this study, newly prepared 5′-deletion and site-directed mutants have been compared both for InsP3 binding and InsP3 3-kinase activity. When the protein was expressed from L259 to R459, the activity was lost but InsP3 binding was conserved. Another deletion mutant that had lost only four amino acids after L259 had lost InsP3 binding, and this finding suggests that these residues (i.e. L259DCK262) are involved in InsP3 binding. To further support the data, we have produced two mutants by site-directed mutagenesis on residues C261 and K262. The two new enzymes were designated M4 (C261S) and M5 (K262A). M4 showed similar Vmax and Km values for InsP3 and ATP to wild-type enzyme. In contrast, M5 was totally inactive but had kept the ability to bind to calmodulin–Sepharose. C-terminal deletion mutants that had lost five, seven or nine amino acids showed a large decrease in InsP3 binding and InsP3 3-kinase activity. One mutant that had lost five amino acids (M2) was purified to apparent homogeneity: Km values for both substrates appeared unchanged but Vmax was decreased approx. 40-fold compared with the wild-type enzyme. The results indicate that (1) a positively charged amino acid residue K262 is essential for InsP3 binding and (2) amino acids at the C-terminal end of the protein are necessary to act as a catalyst in the InsP3 3-kinase reaction.

scholarly journals A trapped human PPM1A–phosphopeptide complex reveals structural features critical for regulation of PPM protein phosphatase activity

2018 ◽  
Vol 293 (21) ◽  
pp. 7993-8008 ◽  
Author(s):  
Subrata Debnath ◽  
Dalibor Kosek ◽  
Harichandra D. Tagad ◽  
Stewart R. Durell ◽  
Daniel H. Appella ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Metal Ions ◽  
Active Site ◽  
Metal Binding ◽  
Metal Ion ◽  
Catalytic Domain ◽  
Protein Phosphatases ◽  
Random Order ◽  
Structural Features

Metal-dependent protein phosphatases (PPM) are evolutionarily unrelated to other serine/threonine protein phosphatases and are characterized by their requirement for supplementation with millimolar concentrations of Mg2+ or Mn2+ ions for activity in vitro. The crystal structure of human PPM1A (also known as PP2Cα), the first PPM structure determined, displays two tightly bound Mn2+ ions in the active site and a small subdomain, termed the Flap, located adjacent to the active site. Some recent crystal structures of bacterial or plant PPM phosphatases have disclosed two tightly bound metal ions and an additional third metal ion in the active site. Here, the crystal structure of the catalytic domain of human PPM1A, PPM1Acat, complexed with a cyclic phosphopeptide, c(MpSIpYVA), a cyclized variant of the activation loop of p38 MAPK (a physiological substrate of PPM1A), revealed three metal ions in the active site. The PPM1Acat D146E–c(MpSIpYVA) complex confirmed the presence of the anticipated third metal ion in the active site of metazoan PPM phosphatases. Biophysical and computational methods suggested that complex formation results in a slightly more compact solution conformation through reduced conformational flexibility of the Flap subdomain. We also observed that the position of the substrate in the active site allows solvent access to the labile third metal-binding site. Enzyme kinetics of PPM1Acat toward a phosphopeptide substrate supported a random-order, bi-substrate mechanism, with substantial interaction between the bound substrate and the labile metal ion. This work illuminates the structural and thermodynamic basis of an innate mechanism regulating the activity of PPM phosphatases.

scholarly journals Crystal structures of catalytic core domain of BIV integrase: implications for the interaction between integrase and target DNA

2010 ◽  
Vol 1 (4) ◽  
pp. 363-370 ◽  
Author(s):  
Xue Yao ◽  
Shasha Fang ◽  
Wentao Qiao ◽  
Yunqi Geng ◽  
Yuequan Shen
Keyword(s):  
Crystal Structures ◽  
Catalytic Core Domain ◽  
Catalytic Core ◽  
Core Domain ◽  
Target Dna
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