Altered Substrate Specificities by Substitutions at Tyr 218 in Bacterial Aminoglycoside 3'- Phosphotransferase – II

Date

1992-06-01

Author

Kocabıyık, Semra

Metadata

Show full item record

Item Usage Stats

35
views

0
downloads

Mutant aminoglycoside 3'-phosphotransferase II enzymes were produced in which Tyr218 was changed to serine, aspartic acid, or phenylalanine. In each case the mutation resulted in increased bacterial susceptibility to neomycin and kanamycin, while simultaneously increasing the Km values for these substrates. For the Ser and Asp mutants, bacterial resistance to amikacin increased, with a concomitant increase in affinity for this drug. Initial velocity studies indicated that the wild-type and mutant enzymes all followed Michaelis-Menten kinetics. Although these mutagenic substitutions changed the substrate specificity of these enzymes they did not alter the enzyme affinity for Mg(2+)-ATP.

URI

https://hdl.handle.net/11511/71172

Journal

FEMS Microbiol. Lett

DOI

https://doi.org/10.1016/0378-1097(92)90529-w

Collections

Department of Biology, Article

Suggestions

OpenMETU
Core

Increasing clavulanic acid production both in wild type and industrial streptomyces clavuligerus strains by amplification of positive regulator claR gene Mutlu, Alper; Özcengiz, Gülay; Department of Biology (2012) Streptomyces clavuligerus is a Gram-positive, filamentous bacterium which produces several important secondary metabolites, including isopenicillin N, cephamycin C and the β-lactamase inhibitor clavulanic acid. Among these compounds, clavulanic acid is being used in combination with commonly used β-lactam antibiotics in order to fight against bacterial infections that are resistant to such antibiotics. Among these combinations, Augmentin, composed of amoxicillin and clavulanic acid, is the most widely presc...
Higher alkyl sulfatase activity required by microbial inhabitants to remove anionic surfactants in the contaminated surface waters İçgen, Bülent; Goksu, Lale; Ulusoy, Huseyin; Yılmaz, Fadime (IWA Publishing, 2017-11-01) Biodegradation of anionic surfactants, like sodium dodecyl sulfate (SDS) are challenged by some bacteria through the function of the enzyme alkyl sulfatases. Therefore, identifying and characterizing bacteria capable of degrading SDS with high alkyl sulfatase enzyme activity are pivotal. In this study, bacteria isolated from surfactant contaminated river water were screened for their potential to degrade SDS. Primary screening carried out by the conventional enrichment culture technique and assessment of SD...
Changes in Free Amino Acid and Sugar Levels of Dried Figs during Aflatoxin B(1) Production by Aspergillus flavus and Aspergillus parasiticus Senyuva, Hamide Z.; Gilbert, John; Ozturkoglu, Sebnem; Özcan Kabasakal, Süreyya; Gurel, Neslihan (American Chemical Society (ACS), 2008-10-22) An aqueous slurry of gamma-irradiated sterilized dried figs was inoculated with toxigenic strains of Aspergillus flavus and Aspergillus parasiticus. During incubation at 28 degrees C, pH, fructose, glucose, and free amino acids were determined by high-performance liquid chromatography and liquid chromatography (LC)/mass spectrometry, respectively, over 13 time points (1-20 days). At the same 13 time points using a LC/time-of-flight mass spectrometry screening method, aflatoxin B, and other secondary metabol...
Regulatory effects of alanine-group amino acids on serine alkaline protease production by recombinant Bacillus licheniformis Çalık, Pınar; Ozdamar, TH (Wiley, 2003-04-01) Influences of the concentration and addition time of alanine-group amino acids, i.e. alanine, leucine and valine, on serine alkaline protease (SAP) synthesis were investigated by Bacillus licheniformis (DSM 1969) carrying pHV1431::subC in a defined medium to identify the amino acids creating intracellular reaction-rate limitation in SAP production. While the precursors of alanine-group amino acids, pyruvate and alanine, did not affect SAP production considerably within the range 0-15 mM, the addition of leu...
The regulatory effect of CcaR activator on the cephamycin C gene cluster of streptomyces clavuligerus Kurt, Aslıhan; Özcengiz, Gülay; Department of Biology (2011) Streptomyces clavuligerus produces industrially important secondary metabolites such as cephamycin C (a β-lactam antibiotic) and clavulanic acid (a potent β-lactamase inhibitor). Cephamycin C is active against penicillin-resistant bacteria due to presence of methoxyl group in C-7 position of cephalosporin nucleus. Clavulanic acid is prescribed in combination with β-lactams for treatment of various bacterial infections. Cephamycin C and clavulanic acid gene clusters form β-lactam supercluster in S. clavulige...

Citation Formats

S. Kocabıyık, “Altered Substrate Specificities by Substitutions at Tyr 218 in Bacterial Aminoglycoside 3′- Phosphotransferase – II,” FEMS Microbiol. Lett, pp. 199–202, 1992, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/71172.