Cloning and expression of periplasmic (clp p-like) and membrane-bound serine protease genes of thermoplasma volcanium in escherichia coli

Demirok, Burçak
Serine proteases are a family of proteases that utilize an activated serine residue in the substrate-binding pocket to catalytically hydrolyze peptide bonds. Enzymes which belong to this family, with a diverse array of metabolic and regulatory functions, play critical roles in cell physiology and pathology. ءClp̕s are a class of ATP dependent serine proteases which are composed of a protease (ClpP) and an ATPase (ClpA or ClpX) component. Their involvements in degrading proteins are especially implicated under stress conditions. In contrast to members of Bacteria and Eukarya, little is known about the energy-dependent proteolysis and there is no report on Clp family proteases in Archaea. In this study, for the fist time, a periplasmic Clp P-like (PSP) and a membrane bound serine protease (MSP) genes from thermophilic archaeon Thermoplasma volcanium GSS1 were cloned and expressed in E. coli. PCR amplifications at 55 ð C yielded unique fragments of 971 and 1521bp, for PSP and MSP genes, respectively, which were ligated to p-Drive cloning vectors and introduced into E.coli TG1 competent cells. Recombinant clones were screened depending on blue/white colony selection. Putative recombinant plasmids were analyzed by restriction enzyme digestions. Serine protease activities of the three positive clones (E. coli TG-S1, E. coli TG-S4 and E. coli TG-M1) were determined spectrophotometrically by using chromogenic oligopeptide substrates. These results indicated that cloned PSP and MSP genes were successfully expressed in E. coli under the control of their own promoters. Heterologous expression of PSP gene was also attempted by adding 6xHis tag to the 5énd of the PSP gene in pQE 30 expression vector. Competent E.coli TG1 cells were transformed by pQE expression constructs. Positive clones were detected on colony blots using Anti-His HRP conjugates and chromogenic DAB substrate.


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Koyuncu, Bilsev; Kocabıyık, Semra; Department of Biology (2006)
Acid proteases, commonly known as aspartic proteases are degredative enzymes which catalyze the cleavage reaction of peptide bonds in proteins with a pH optimum in the acidic range (pH 3-4). Acid proteases have crucial roles in metabolism. Moreover, they are used in different fields of industry. Thermophilic microorganisms, especially archaea, gain special interest because of their thermal stability for both fundamental and industrial researches. Thermopsin is an extracellular acid protease and a member of ...
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Persil Çetinkol, Özgül (Oxford University Press (OUP), 2009-02-01)
A few drug-like molecules have recently been found to bind poly(A) and induce a stable secondary structure (T(m)approximate to 60 degrees C), even though this RNA homopolymer is single-stranded in the absence of a ligand. Here, we report results from experiments specifically designed to explore the association of small molecules with poly(A). We demonstrate that coralyne, the first small molecule discovered to bind poly(dA), binds with unexpectedly high affinity (K(a) >10(7) M(-1)), and that the crescent sh...
Live-cell imaging of Pol II promoter activity to monitor gene expression with RNA IMAGEtag reporters
SHIN, Ilchung; RAY, Judhajeet; Gupta, Vinayak; İlgü, Müslüm; Beasley, Jonathan; BENDICKSON, Lee; MEHANOVIC, Samir; Kraus, George A.; Nilsen-Hamilton, Marit (Oxford University Press (OUP), 2014-01-01)
We describe a ribonucleic acid (RNA) reporter system for live-cell imaging of gene expression to detect changes in polymerase II activity on individual promoters in individual cells. The reporters use strings of RNA aptamers that constitute IMAGEtags (Intracellular MultiAptamer GEnetic tags) that can be expressed from a promoter of choice. For imaging, the cells are incubated with their ligands that are separately conjugated with one of the FRET pair, Cy3 and Cy5. The IMAGEtags were expressed in yeast from ...
Molecular dynamics simulations and coupled nucleotide substitution experiments indicate the nature of A center dot A base pairing and a putative structure of the coralyne-induced homo-adenine duplex
Joung, In Suk; Persil Çetinkol, Özgül; HUD, Nicholas V.; Cheatham, Thomas E. (Oxford University Press (OUP), 2009-12-01)
Coralyne is an alkaloid drug that binds homo-adenine DNA (and RNA) oligonucleotides more tightly than it does Watson-Crick DNA. Hud's laboratory has shown that poly(dA) in the presence of coralyne forms an anti-parallel duplex, however attempts to determine the structure by NMR spectroscopy and X-ray crystallography have been unsuccessful. Assuming adenine-adenine hydrogen bonding between the two poly(dA) strands, we constructed 40 hypothetical homo-(dA) anti-parallel duplexes and docked coralyne into the s...
Genetic polymorphisms of alcohol inducible CYP2E1 in Turkish population
Ulusoy, Gülen; Adalı, Orhan; Department of Biochemistry (2004)
Cytochrome P4502E1 (CYP2E1), the ethanol-inducible isoform of cytochrome P450 superfamily, catalyzes many low molecular weight endogenous and exogenous compounds, including ethanol, acetone, drugs like acetaminophen and chlorzoxazone, and industrial solvents like benzene and styrene, most of which are carcinogenic. Besides, it has a high capacity to produce reactive oxygen species. CYP2E1 is induced by ethanol and isoniazid, as well by some pathophysiological conditions like diabetes and starvation. CYP2E1 ...
Citation Formats
B. Demirok, “Cloning and expression of periplasmic (clp p-like) and membrane-bound serine protease genes of thermoplasma volcanium in escherichia coli,” M.S. - Master of Science, Middle East Technical University, 2006.