Search results for "Erich"
showing 10 items of 805 documents
Contact sites of peptide-oligoribonucleotide cross-links identified by a combination of peptide and nucleotide sequencing with MALDI MS.
1997
We have investigated peptide–oligoribonucleotide complexes isolated from cross-linked Escherichia coli 30S ribosomal subunits in order to identify the contact sites of these complexes at the molecular level. For this purpose, reversed-phase (RP) HPLC-purified peptide–oligoribonucleotide complexes were submitted to N-terminal amino acid sequencing in order to determine the cross-linked peptide moiety and were analyzed using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) for calculation of the nucleotide composition of the cross-linked complex. Subsequently, for nucleotide sequence information the complexes were partially hydrolyzed or treated with exonucleases and a…
Polymer-induced phase separation in suspensions of bacteria
2010
We study phase separation in suspensions of two unrelated species of rod-like bacteria, Escherichia coli and Sinorhizobium meliloti, induced by the addition of two different anionic polyelectrolytes, sodium polystyrene sulfonate or succinoglycan, the former being synthetic and the latter of natural origin. Comparison with the known behaviour of synthetic colloid-polymer mixtures and with simulations show that "depletion" (or, equivalently, "macromolecular crowding") is the dominant mechanism: exclusion of the non-adsorbing polymer from the region between two neighbouring bacteria creates an unbalanced osmotic force pushing them together. The implications of our results for understanding phe…
Identification of the 3-amino-3-carboxypropyl (acp) transferase enzyme responsible for acp3U formation at position 47 in Escherichia coli tRNAs
2019
AbstracttRNAs from all domains of life contain modified nucleotides. However, even for the experimentally most thoroughly characterized model organism Escherichia coli not all tRNA modification enzymes are known. In particular, no enzyme has been found yet for introducing the acp3U modification at position 47 in the variable loop of eight E. coli tRNAs. Here we identify the so far functionally uncharacterized YfiP protein as the SAM-dependent 3-amino-3-carboxypropyl transferase catalyzing this modification and thereby extend the list of known tRNA modification enzymes in E. coli. Similar to the Tsr3 enzymes that introduce acp modifications at U or m1Ψ nucleotides in rRNAs this protein conta…
The dcuD (former yhcL ) gene product of Escherichia coli as a member of the DcuC family of C4-dicarboxylate carriers: lack of evident expression
1999
The dcuD gene (formerly yhcL) of Escherichia coli shows significant sequence similarity only to the dcuC gene of E. coli, which encodes a C4-dicarboxylate carrier (DcuC) that functions during anaerobic growth. Inactivation of dcuD had no effect on the growth of E. coli under a large number of conditions and led to no detectable changes in phenotype. Translational dcuD'-'lacZ gene fusions were not significantly expressed in the presence of dicarboxylates or monocarboxylates under oxic or anoxic conditions. Other potential substrates such as amino sugar derivatives, amino acids, and alpha-aspartyl dipeptides also did not lead to expression of dcuD. Changes in medium composition, pH, ionic str…
The gene encoding polyneuridine aldehyde esterase of monoterpenoid indole alkaloid biosynthesis in plants is an ortholog of theα/β hydrolase super fa…
2000
The biosynthesis of the anti-arrhythmic alkaloid ajmaline is catalysed by more than 10 specific enzymes. In this multistep process polyneuridine aldehyde esterase (PNAE) catalyses a central reaction by transforming polyneuridine aldehyde into epi-vellosimine, which is the immediate precursor for the synthesis of the ajmalane skeleton. PNAE was purified from cell suspension cultures of Rauvolfia serpentina. The N-terminal sequence and endoproteinase LysC fragments of the purified protein were used for primer design and for the amplification of specific PCR products leading to the isolation of PNAE-encoding cDNA from a R. serpentina library. The PNAE cDNA was fused with a C-terminal His-tag, …
Identification of Gip as a novel phage-encoded gyrase inhibitor protein featuring a broad activity profile
2021
AbstractBacteriophages represent a powerful source for the identification of novel antimicrobial proteins. In this study, a screening of small cytoplasmic proteins encoded by the CGP3 prophage of Corynebacterium glutamicum, resulted in the identification of the novel gyrase-inhibiting protein Cg1978 (Gip), which shows a direct interaction with the gyrase subunit A (GyrA). In vitro supercoiling assays further suggest a stabilization of the cleavage complex by Gip. Overproduction of Gip in C. glutamicum resulted in a severe growth defect as well as an induction of the SOS response. The cells adapted to gip overexpression by increasing expression levels of gyrAB and by reducing topA expression…
Genetic Systems for Monitoring Interactions of Transmembrane Domains in Bacterial Membranes
2013
In recent years several systems have been developed to study interactions of TM domains within the inner membrane of the Gram-negative bacterium Escherichia coli. Mostly, a transmembrane domain of interest is fused to a soluble DNA-binding domain, which dimerizes in E. coli cytoplasm after interactions of the transmembrane domains. The dimeric DNA-binding domain subsequently binds to a promoter/operator region and thereby activates or represses a reporter gene. In 1996 the first bacterial system has been introduced to measure interactions of TM helices within a bacterial membrane, which is based on fusion of a transmembrane helix of interest to the DNA-binding domain of the Vibrio cholerae …
ElaC Encodes a Novel Binuclear Zinc Phosphodiesterase
2002
ElaC is a widespread gene found in eubacteria, archaebacteria, and mammals with a highly conserved sequence. Two human ElaC variants were recently associated with cancer (Tavtigian, S. V., Simard, J., Teng, D. H., Abtin, V., Baumgard, M., Beck, A., Camp, N. J., Carillo, A. R., Chen, Y., Dayananth, P., Desrochers, M., Dumont, M., Farnham, J. M., Frank, D., Frye, C., Ghaffari, S., Gupte, J. S., Hu, R., Iliev, D., Janecki, T., Kort, E. N., Laity, K. E., Leavitt, A., Leblanc, G., McArthur-Morrison, J., Pederson, A., Penn, B., Peterson, K. T., Reid, J. E., Richards, S., Schroeder, M., Smith, R., Snyder, S. C., Swedlund, B., Swensen, J., Thomas, A., Tranchant, M., Woodland, A. M., Labrie, F., Sko…
Epidemic dissemination of Salmonella enterica spp. enterica serovar Bovismorbificans in southern Italy in the years 1989-1991.
1994
Epidemic strains of Salmonella enterica subsp. enterica serovar Bovismorbificans isolated in southern Italy during the years 1989-1991 were submitted to a molecular epidemiological study in comparison with isolates identified in the years 1980-1988 in the same geographic area. Genomic DNA fragments obtained by digestion with BglI or Eco RI hybridized with Escherichia coli rRNA to produce three distinct, but highly related patterns. Ribotype 1, which had never been identified before 1989, was found to characterize most of the strains identified between 1989 and 1991. Such a finding supports the hypothesis of emergence and spread of a new bacterial clone associated with the increased number o…
Caracterización y tipificación molecular de cepas de Escherichia coli y Klebsiella pneumoniae productoras de betalactamasas de espectro extendido (BL…
2021
Introducción: Las betalactamasas de espectro extendido (BLEE) son enzimas producidas principalmente por la familia Enterobacteriaceae y se caracterizan porque inactivan a la práctica totalidad de los antibióticos betalactámicos. El aislamiento clínico de cepas productoras de BLEE es cada vez más frecuente en todo el mundo. Diferentes especies de Enterobacterales pueden ser productoras de BLEE, pero Klebsiella pneumoniae y Escherichia coli son las especies que las producen mayoritariamente. La realización de estudios de caracterización epidemiológica de las cepas productoras de BLEE es fundamental para detectar cualquier cambio en la resistencia y por tanto, para el control de su diseminació…