Search results for "P'"

6-thio-GTP Derivatives

2006

Binding and/or hydrolysis of purine‐based nucleotides is not required for IM30 ring formation

2021

IM30, the inner membrane-associated protein of 30 kDa, is conserved in cyanobacteria and chloroplasts. Although its exact physiological function is still mysterious, IM30 is clearly essential for thylakoid membrane biogenesis and/or dynamics. Recently, a cryptic IM30 GTPase activity has been reported, albeit thus far no physiological function has been attributed to this. Yet, it is still possible that GTP binding/hydrolysis affects formation of the prototypical large homo-oligomeric IM30 ring and rod structures. Here, we show that the Synechocystis sp. PCC 6803 IM30 protein in fact is an NTPase that hydrolyzes GTP and ATP, but not CTP or UTP, with about identical rates. While IM30 forms lar…

Regulated expression and phosphorylation of the 23-26-kDa ras protein in the sponge Geodia cydonium.

1990

We have cloned, sequenced and examined the sponge Geodia cydonium cDNA encoding a protein homologous to ras proteins. The sponge ras protein has a more conserved N-terminal region and a less conserved C-terminal region, especially in comparison to Dictyostelium discoideum; the similarity to human c-Ha-ras-1 and to Saccharomyces cerevisiae is less pronounced. The sponge ras cDNA comprises five TAG triplets; at the translational level these UAG termination codons are suppressed by a Gln-tRNA. The sponge ras protein was isolated and partially purified (23-26 kDa) and found to undergo phosphorylation at a threonine moiety, when dissociated cells were incubated in the presence of a homologous ag…

Molecular recognition of nucleotides in water by scorpiand-type receptors based on nucleobase discrimination.

2014

Abstract: The detection of nucleotides is of crucial impor-tance because they are the basic building blocks of nucleicacids. Scorpiand-based polyamine receptors functionalizedwith pyridine or anthracene units are able to form stablecomplexes with nucleotides in water, based on coulombic,p–p stacking, and hydrogen-bonding interactions. This be-havior has been rationalized by means of an explorationwith NMR spectroscopy and DFT calculations. Binding con-stants were determined by potentiometry. Fluorescencespectroscopy studies have revealed the potential of these re-ceptors as sensors to effectively and selectively distinguishguanosine-5’-triphosphate (GTP) from adenosine-5’-triphos-phate (ATP…

Selective Stimulation of Hepatitis C Virus and Pestivirus NS5B RNA Polymerase Activity by GTP

1999

NS5B of the hepatitis C virus is an RNA template-dependent RNA polymerase and therefore the key player of the viral replicase complex. Using a highly purified enzyme expressed with recombinant baculoviruses in insect cells, we demonstrate a stimulation of RNA synthesis up to 2 orders of magnitude by high concentrations of GTP but not with ATP, CTP, UTP, GDP, or GMP. Enhancement of RNA synthesis was found with various heteropolymeric RNA templates, with poly(C)-oligo(G)12 but not with poly(A)-oligo(U)12. Several amino acid substitutions in polymerase motifs B, C, and D previously shown to be crucial for RdRp activity were tested for GTP stimulation of RNA synthesis. Most of these mutations, …

PURINE AND PYRIMIDINE NUCLEOTIDES IN THE BRAIN OF NORMAL AND CONVULSANT RATS

1969

— Purine and pyrimidine nucleotides were measured in the brain of normal and electroshocked rats after chromatographic separation on ion-exchange resin of mono-, di- and tri-phosphorylated derivatives. CMP, IMP and NAD did not show any significant quantitative change. Adenine nucleotides showed an abrupt change followed by a rapid return to the control value. GTP was the only purine nucleotide exhibiting a relatively slow return to its starting concentration. The greatest percentage increase after electroshock was observed in UMP, which returned to its control value only after 5 min; UDPCoenzymes (i.e. UDPA plus UDPG) showed a relatively small drop during the development of the seizure and …

Occurrence of Kemp's ridley sea turtle ( Lepidochelys kempii) in the Mediterranean

2008

Recent reports of Kemp's ridley sea turtle (Lepidochelys kempii) in the Western Mediterranean calls for a re-assessment of the relative importance and the presence of this species in this sea. Different hypotheses to account for the increase in reports are discussed. The present note provides a new report of the species, a juvenile of 28 cm curved carapace length caught close to Valencia (east Spain) on 16 July 2006. Conservation measures in the area should consider this species in the near future.

Structural insights into the GTPase domain of Escherichia coli MnmE protein

2007

The Escherichia coli MnmE protein is a 50-kDa multidomain GTPase involved in tRNA modification. Its homologues in eukaryotes are crucial for mitochondrial respiration and, thus, it is thought that the human protein might be involved in mitochondrial diseases. Unlike Ras, MnmE shows a high intrinsic GTPase activity and requires effective GTP hydrolysis, and not simply GTP binding, to be functionally active. The isolated MnmE G-domain (165 residues) conserves the GTPase activity of the entire protein, suggesting that it contains the catalytic residues for GTP hydrolysis. To explore the GTP hydrolysis mechanism of MnmE, we analyzed the effect of low pH on binding and hydrolysis of GTP, as well…

Apogeum i kres stalinowskich obchodów Święta Pracy na Śląsku Opolskim (część 2)

2017

The article analyses the course of the May Day celebrations in Opole Silesia. Starting early in the morning on the Labourer's Day, propaganda slogans and reports of accomplished May Day actions were broadcast, and delegates from various workplaces, organisations and institutions gathered in order to participate in the manifestations. The main culminating point of the celebration agenda was the parade which set off after speeches delivered by the representatives of the party authorities. The parades were organised in all of the cities and all the commune centres. The parade in Opole had the largest number of participants in the region - in 1955, it gathered 50,000 people. Individual workplac…

Sylow permutable subnormal subgroups of finite groups II

2001

[EN] In this paper a local version of Agrawal's theorem about the structure of finite groups in which Sylow permutability is transitive is given. The result is used to obtain new characterisations of this class of finite groups.