scholarly journals An extremely thermostable aldolase from Sulfolobus solfataricus with specificity for non-phosphorylated substrates

1999 ◽  
Vol 343 (3) ◽  
pp. 563-570 ◽  
Author(s):  
Catriona L. BUCHANAN ◽  
Helen CONNARIS ◽  
Michael J. DANSON ◽  
Christopher D. REEVE ◽  
David W. HOUGH
Keyword(s):  
Catalytic Mechanism ◽  
Sequence Similarity ◽  
Sulfolobus Solfataricus ◽  
Kinetic Properties ◽  
Cloning And Sequencing ◽  
Gene Encoding ◽  
Expression In Escherichia Coli ◽  
Carbon Carbon Bond ◽  
Step Procedure ◽  
Dependent Inactivation

Sulfolobus solfataricus is a hyperthermophilic archaeon growing optimally at 80-85 °C. It metabolizes glucose via a novel non-phosphorylated Entner-Doudoroff pathway, in which the reversible C6 to C3 aldol cleavage is catalysed by 2-keto-3-deoxygluconate aldolase (KDG-aldolase), generating pyruvate and glyceraldehyde. Given the ability of such a hyperstable enzyme to catalyse carbon-carbon-bond synthesis with non-phosphorylated metabolites, we report here the cloning and sequencing of the S. solfataricus gene encoding KDG-aldolase, and its expression in Escherichia coli to give fully active enzyme. The recombinant enzyme was purified in a simple two-step procedure, and shown to possess kinetic properties indistinguishable from the enzyme purified from S. solfataricuscells. The KDG-aldolase is a thermostable tetrameric protein with a half-life at 100 °C of 2.5 h, and is equally active with both D- and L-glyceraldehyde. It exhibits sequence similarity to the N-acetylneuraminate lyase superfamily of Schiff-base-dependent aldolases, dehydratases and decarboxylases, and evidence is presented for a similar catalytic mechanism for the archaeal enzyme by substrate-dependent inactivation by reduction with NaBH4.

scholarly journals Identification and characterization of the gene encoding the human phosphopantetheine adenylyltransferase and dephospho-CoA kinase bifunctional enzyme (CoA synthase)

2002 ◽  
Vol 365 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Suren AGHAJANIAN ◽  
D.Margaret WORRALL
Keyword(s):  
Biosynthetic Pathway ◽  
Sequence Similarity ◽  
Kinetic Properties ◽  
Sequence Information ◽  
Bifunctional Enzyme ◽  
Gene Encoding ◽  
Pig Liver ◽  
Identification And Characterization ◽  
Similar Kinetic

The final two enzymes in the CoA biosynthetic pathway, phosphopantetheine adenylyltransferase (PPAT; EC 2.7.7.3) and dephospho-CoA kinase (DPCK; EC 2.7.1.24), are separate proteins in prokaryotes, but exist as a bifunctional enzyme in pig liver. In the present study we have obtained sequence information from purified pig-liver enzyme, and identified the corresponding cDNA in a number of species. The human gene localizes to chromosome 17q12-21 and contains regions with sequence similarity to the monofunctional Escherichia coli DPCK and PPAT. The recombinant 564-amino-acid human protein confirmed the associated transferase and kinase activities, and gave similar kinetic properties to the wild-type pig enzyme.

scholarly journals Cloning and Sequencing of a Poly(dl-Lactic Acid) Depolymerase Gene from Paenibacillus amylolyticus Strain TB-13 and Its Functional Expression in Escherichia coli

2003 ◽  
Vol 69 (5) ◽  
pp. 2498-2504 ◽  
Author(s):  
Yukie Akutsu-Shigeno ◽  
Teerawat Teeraphatpornchai ◽  
Kamonluck Teamtisong ◽  
Nobuhiko Nomura ◽  
Hiroo Uchiyama ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Amino Acid ◽  
Functional Expression ◽  
Amino Acid Residues ◽  
Cloning And Sequencing ◽  
Gene Encoding ◽  
Butylene Succinate ◽  
Expression In Escherichia Coli ◽  
Poly Ethylene

ABSTRACT The gene encoding a poly(dl-lactic acid) (PLA) depolymerase from Paenibacillus amylolyticus strain TB-13 was cloned and overexpressed in Escherichia coli. The purified recombinant PLA depolymerase, PlaA, exhibited degradation activities toward various biodegradable polyesters, such as poly(butylene succinate), poly(butylene succinate-co-adipate), poly(ethylene succinate), and poly(ε-caprolactone), as well as PLA. The monomeric lactic acid was detected as the degradation product of PLA. The substrate specificity toward triglycerides and p-nitrophenyl esters indicated that PlaA is a type of lipase. The gene encoded 201 amino acid residues, including the conserved pentapeptide Ala-His-Ser-Met-Gly, present in the lipases of mesophilic Bacillus species. The identity of the amino acid sequence of PlaA with Bacillus lipases was no more than 45 to 50%, and some of its properties were different from those of these lipases.

Cloning and sequencing of the gene encoding thermostable elongation factor 2 in Sulfolobus solfataricus

Gene ◽  
1993 ◽  
Vol 136 (1-2) ◽  
pp. 41-48 ◽  
Author(s):  
Emmanuele De Vendittis ◽  
Maria Rosaria Amatruda ◽  
Mariorosario Masullo ◽  
Vincenzo Bocchini
Keyword(s):  
Sulfolobus Solfataricus ◽  
Elongation Factor ◽  
Cloning And Sequencing ◽  
Gene Encoding ◽  
Elongation Factor 2

scholarly journals Escherichia coli exonuclease VII. Cloning and sequencing of the gene encoding the large subunit (xseA).

1986 ◽  
Vol 261 (32) ◽  
pp. 14929-14935
Author(s):  
J W Chase ◽  
B A Rabin ◽  
J B Murphy ◽  
K L Stone ◽  
K R Williams
Keyword(s):  
Escherichia Coli ◽  
Large Subunit ◽  
Cloning And Sequencing ◽  
Gene Encoding ◽  
Exonuclease Vii

scholarly journals Signaling through Adenylyl Cyclase Is Essential for Hyphal Growth and Virulence in the Pathogenic FungusCandida albicans

2001 ◽  
Vol 12 (11) ◽  
pp. 3631-3643 ◽  
Author(s):  
Cintia R. C. Rocha ◽  
Klaus Schröppel ◽  
Doreen Harcus ◽  
Anne Marcil ◽  
Daniel Dignard ◽  
...  
Keyword(s):  
Mouse Model ◽  
Adenylyl Cyclase ◽  
Sequence Similarity ◽  
Hyphal Growth ◽  
Antifungal Drugs ◽  
Growth Defect ◽  
Adenylyl Cyclases ◽  
Gene Encoding ◽  
Mutant Cells

The human fungal pathogen Candida albicans switches from a budding yeast form to a polarized hyphal form in response to various external signals. This morphogenetic switching has been implicated in the development of pathogenicity. We have cloned theCaCDC35 gene encoding C. albicansadenylyl cyclase by functional complementation of the conditional growth defect of Saccharomyces cerevisiae cells with mutations in Ras1p and Ras2p. It has previously been shown that these Ras homologues regulate adenylyl cyclase in yeast. The C. albicans adenylyl cyclase is highly homologous to other fungal adenylyl cyclases but has less sequence similarity with the mammalian enzymes. C. albicans cells deleted for both alleles ofCaCDC35 had no detectable cAMP levels, suggesting that this gene encodes the only adenylyl cyclase in C. albicans. The homozygous mutant cells were viable but grew more slowly than wild-type cells and were unable to switch from the yeast to the hyphal form under all environmental conditions that we analyzed in vitro. Moreover, this morphogenetic switch was completely blocked in mutant cells undergoing phagocytosis by macrophages. However, morphogenetic switching was restored by exogenous cAMP. On the basis of epistasis experiments, we propose that CaCdc35p acts downstream of the Ras homologue CaRas1p. These epistasis experiments also suggest that the putative transcription factor Efg1p and components of the hyphal-inducing MAP kinase pathway depend on the function of CaCdc35p in their ability to induce morphogenetic switching. Homozygouscacdc35Δ cells were unable to establish vaginal infection in a mucosal membrane mouse model and were avirulent in a mouse model for systemic infections. These findings suggest that fungal adenylyl cyclases and other regulators of the cAMP signaling pathway may be useful targets for antifungal drugs.

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