Hemolytic properties and riboflavin synthesis of Helicobacter pylori: cloning and functional characterization of the rib A gene encoding GTP-cyclohydrolase II that confers hemolytic activity to Escherichia coli

1998 ◽  
Vol 186 (4) ◽  
pp. 177-187 ◽  
Author(s):  
S. Bereswill ◽  
F. Fassbinder ◽  
C. Völzing ◽  
A. Covacci ◽  
R. Haas ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Helicobacter Pylori ◽  
Hemolytic Activity ◽  
Functional Characterization ◽  
Gtp Cyclohydrolase ◽  
Gene Encoding ◽  
Gtp Cyclohydrolase Ii ◽  
Riboflavin Synthesis

scholarly journals Tools for Characterization of Escherichia coli Genes of Unknown Function

2002 ◽  
Vol 184 (16) ◽  
pp. 4573-4581 ◽  
Author(s):  
Christophe Merlin ◽  
Sean McAteer ◽  
Millicent Masters
Keyword(s):  
Escherichia Coli ◽  
Target Gene ◽  
Target Genes ◽  
Functional Characterization ◽  
Phenotypic Characterization ◽  
Gene Encoding ◽  
Flp Recombinase ◽  
Short Scar

ABSTRACT Despite the power of sequencing and of emerging high-throughput technologies to collect data rapidly, the definitive functional characterization of unknown genes still requires biochemical and genetic analysis in case-by-case studies. This often involves the deletion of target genes and phenotypic characterization of the deletants. We describe here modifications of an existing deletion method which facilitates the deletion process and enables convenient analysis of the expression properties of the target gene by replacing it with an FRT-lacZ-aph-Plac -FRT cassette. The lacZ gene specifically reports the activity of the deleted gene and therefore allows the determination of the conditions under which it is actively expressed. The aph gene, encoding resistance to kanamycin, provides a selectable means of transducing a deleted locus between strains so that the deletion can be combined with other relevant mutations. The lac promoter helps to overcome possible polar effects on downstream genes within an operon. Because the cassette is flanked by two directly repeated FRT sites, the cassette can be excised by the Flp recombinase provided in trans. Removing the cassette leaves an in-frame deletion with a short scar which should not interfere with downstream expression. Replacements of yacF, yacG, yacH, yacK (cueO), yacL, ruvA, ruvB, yabB, and yabC made with the cassette were used to verify its properties.

scholarly journals Structural and functional characterization of the receptor binding proteins of Escherichia coli O157 phages EP75 and EP335

2021 ◽  
Author(s):  
Sander Witte ◽  
Léa V. Zinsli ◽  
Rafael Gonzalez-Serrano ◽  
Cassandra I. Matter ◽  
Martin J. Loessner ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Receptor Binding ◽  
Binding Proteins ◽  
Functional Characterization ◽  
Escherichia Coli O157

Identification and functional characterization of levS, a gene encoding for a levansucrase from Leuconostoc mesenteroides NRRL B-512 F

Gene ◽  
2006 ◽  
Vol 376 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Sandra Morales-Arrieta ◽  
Maria Elena Rodríguez ◽  
Lorenzo Segovia ◽  
Agustín López-Munguía ◽  
Clarita Olvera-Carranza
Keyword(s):  
Leuconostoc Mesenteroides ◽  
Functional Characterization ◽  
Gene Encoding

Molecular characterization of three mutations in katG affecting the activity of hydroperoxidase I of Escherichia coli

1990 ◽  
Vol 68 (7-8) ◽  
pp. 1037-1044 ◽  
Author(s):  
Peter C. Loewen ◽  
Jacek Switala ◽  
Mark Smolenski ◽  
Barbara L. Triggs-Raine
Keyword(s):  
Escherichia Coli ◽  
Specific Activity ◽  
Polymerase Chain Reaction Amplification ◽  
Protein A ◽  
Wild Type ◽  
Wild Type Enzyme ◽  
Gene Encoding ◽  
Reaction Amplification ◽  
Mutant Genes

Hydroperoxidase I (HPI) of Escherichia coli is a bifunctional enzyme exhibiting both catalase and peroxidase activities. Mutants lacking appreciable HPI have been generated using nitrosoguanidine and the gene encoding HPI, katG, has been cloned from three of these mutants using either classical probing methods or polymerase chain reaction amplification. The mutant genes were sequenced and the changes from wild-type sequence identified. Two mutants contained G to A changes in the coding strand, resulting in glycine to aspartate changes at residues 119 (katG15) and 314 (katG16) in the deduced amino acid sequence of the protein. A third mutant contained a C to T change resulting in a leucine to phenylalanine change at residue 139 (katG14). The Phe139-, Asp119-, and Asp314-containing mutants exhibited 13, < 1, and 18%, respectively, of the wild-type catalase specific activity and 43, 4, and 45% of the wild-type peroxidase specific activity. All mutant enzymes bound less protoheme IX than the wild-type enzyme. The sensitivities of the mutant enzymes to the inhibitors hydroxylamine, azide, and cyanide and the activators imidazole and Tris were similar to those of the wild-type enzyme. The mutant enzymes were more sensitive to high temperature and to β-mercaptoethanol than the wild-type enzyme. The pH profiles of the mutant catalases were unchanged from the wild-type enzyme.Key words: catalase, hydroperoxidase I, mutants, sequence analysis.

Functional characterization of the antagonistic flagellar late regulators FliA and FlgM of Helicobacter pylori and their effects on the H. pylori transcriptome

2002 ◽  
Vol 43 (2) ◽  
pp. 307-322 ◽  
Author(s):  
Christine Josenhans ◽  
Eike Niehus ◽  
Stefanie Amersbach ◽  
Andrea Hörster ◽  
Christian Betz ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Functional Characterization ◽  
H Pylori
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