Disease relevance of yjjX

• Cooperativity in nucleotide binding was observed in many, and sequential NTPase catalysis has been observed in two proteins, gp4 of bacteriophage T7 and rho of Escherichia coli [1].
• A steady-state and pre-steady-state kinetic analysis of the NTPase activity associated with the hepatitis C virus NS3 helicase domain [2].
• We present evidence that poliovirus 2C has nucleoside triphosphatase (NTPase) activity and binds to RNA [3].
• The putative NTPase/helicase protein from severe acute respiratory syndrome coronavirus (SARS-CoV) is postulated to play a number of crucial roles in the viral life cycle, making it an attractive target for anti-SARS therapy [4].
• Isolation and sequencing of the rho gene from Streptomyces lividans ZX7 and characterization of the RNA-dependent NTPase activity of the overexpressed protein [5].

High impact information on yjjX

• Helicases are motor proteins that couple the hydrolysis of nucleoside triphosphate (NTPase) to nucleic acid unwinding [1].
• Limited tryptic digestion of Escherichia coli transcription termination factor rho [an RNA-dependent nucleoside triphosphatase (NTPase)] yields predominantly two fragments (f1 and f2) when the protein is bound to both poly(C) and ATP [6].
• We suggest that rho NTPase is regulated by RNA polymerase (EC 2.7.7.6) so that during transcription elongation the RNA polymerase competes successfully with rho for substrates and inhibits rho NTPase with product pyrophosphate [7].
• The NTPase Walker A active site of the inner membrane protein VirB4 is required for virulence, but an active site VirB4 variant stabilized VirB3 and VirB8 and enabled T-pilus formation [8].
• Both NTPase and pyrophosphatase activities were enhanced at higher temperatures and blocked by the alpha,beta-methyleneadenosine triphosphate, which cannot be hydrolyzed by Tm-MazG [9].

Chemical compound and disease context of yjjX

• Biochemical studies indicate that the M. luteus protein is very similar to E. coli Rho in terms of its RNA-dependent NTPase activity and its sensitivity to the Rho-specific inhibitor bicyclomycin [10].
• The hepatitis C virus nonstructural 3 protein (NS3) possesses a serine protease activity in the N-terminal one-third, whereas RNA-stimulated NTPase and helicase activities reside in the C-terminal portion [11].
• The nucleoside triphosphate hydrolase (NTPase) isoforms termed, NTPase-I and NTPase-II of Toxoplasma gondii, were expressed in Escherichia coli as inclusion bodies and purified under denaturing condition [12].

Biological context of yjjX

• The helicase and NTPase activities of full-length NS3 have been demonstrated and we have characterized the effects of amino acid substitutions on conserved motifs of NS3 helicase [13].
• Southern blotting showed a gene copy number of between one and five, and the possibility that ntp is tandemly repeated over a large length of DNA [14].
• The non-structural protein 3 (NS3) of hepatitis C virus (HCV) possesses three activities which are likely to be essential for virus replication; a serine protease located in the N terminus and helicase and NTPase activities located in the C terminus [13].
• Based on comparative analysis with other related proteins of the Lactobacillus and Lactococcus phages as well as the Escherichia coli phages (such as lambda), functions were putatively assigned to several phi g1e ORFs: cng and cpg (encoding for repressors), hel (helicase), ntp (NTPase), and several ORFs (e.g., minor capsid proteins) [15].
• 5. The substrate specificity was broad and a nonspecific Mg2+-independent ribonucleoside-triphosphatase (NTPase) activity was expressed together with thiamin-triphosphatase activity [16].

Anatomical context of yjjX

• This may be a particular example of a more general class of pattern forming mechanisms, based on protein oligomerization upon a template (membranes, DNA a.o.) with resulting enhanced NTPase function in the oligomer state, which may bring the oligomer into an unstable internal state [17].

Associations of yjjX with chemical compounds

• Further, RNA polymerase pausing may result in reduced pyrophosphate and increased NTP concentrations, allowing rho NTPase to function [7].
• As is true for synthetic polynucleotides known to activate the rho NTPase, the trp t' region has few G residues [18].
• Wild-type rho must bind single-stranded polynucleotides to activate its nucleotide triphosphatase (NTPase) activity, and either poly(C), or poly(dC) plus oligo(C), will suffice [19].
• N-terminal deletion analysis to express a truncated form of Rho (Rho 72, 72 kDa) indicated that the first 42 residues of Rho 77 were not essential for RNA-dependent NTPase activity and were not the targets of inhibition by heparin or bicyclomycin [5].
• Our results reveal that the functional domains required for serine protease and RNA-stimulated NTPase activities map within the region between amino acid residues 160 and 180 of NS3 protein and that a novel motif, the cluster of basic residues 184RKRK, plays an important role for the RNA-stimulated NTPase activity [20].

Other interactions of yjjX

• In the absence of any other viral factors, the fusion product had NTPase, RNA binding and RNA helicase activities [21].

Analytical, diagnostic and therapeutic context of yjjX

• Sequence analysis of the helicase/NTPase domain has identified motifs indicative of the DEAD-box family of helicases [13].
• Northern blotting revealed that the NTPase mRNA was in great abundance and had a length of about 2800 nucleotides [14].
• The NTPase activity of the recombinant DEN1 NS3 protein was characterized using a thin-layer chromatography assay [22].
• From gel filtration analyses, we have determined two fractions containing metabolite-inducible NTPase activities which are independent of GTP-binding protein enzymatic actions [23].
• The test was conducted by using the recombinant NTPase isoforms and comparing the enzyme linked immunosorbent assay (ELISA) absorbances with the Sabin-Feldman dye test titer [12].

References