An RNA-dependent nucleoside triphosphate phosphohydrolase (ATPase) associated with rho termination factor.
نویسندگان
چکیده
Highly purified rho termination factor from Escherichia coli catalyzes an RNA-dependent hydrolysis of ribonucleoside triphosphates to nucleoside diphosphates and inorganic phosphate. In the presence of poly(C), a specific activity of 100 mumole of ATP hydrolyzed per min/mg has been measured. The phosphohydrolase activity appears to be associated with the protein responsible for termination of RNA synthesis, but a functional relationship between the two activities is not yet evident. Hydrolysis of nucleoside triphosphates occurs in the absence of termination and without any extensive degradation of RNA.
منابع مشابه
Vaccinia NPH-I, a DExH-box ATPase, is the energy coupling factor for mRNA transcription termination.
Vaccinia virus RNA polymerase terminates transcription in response to a specific signal UUUUUNU in the nascent RNA. Transduction of this signal to the elongating polymerase requires a trans-acting viral termination factor (VTF/capping enzyme), and is coupled to the hydrolysis of ATP. Recent studies suggest that ATP hydrolysis is catalyzed by a novel termination protein (factor X), which is tigh...
متن کاملCytosine nucleoside inhibition of the ATPase of Escherichia coli termination factor rho: evidence for a base specific interaction between rho and RNA.
The function of rho factor in transcription termination depends on interactions with nascent RNA molecules that contain unpaired cytidylate residues. We show that cytidine, as a free nucleoside, inhibits the binding of rho to lambda cro mRNA and is a competitive inhibitor of rho-ATPase activity with lambda cro mRNA as cofactor. The relative ability of various cytidine analogs and other nucleosi...
متن کاملMutations in the ATP-binding domain of Escherichia coli rho factor affect transcription termination in vivo.
Five mutant rho proteins, representing alterations at three different locations in the Escherichia coli rho gene that affect ATP hydrolytic activity but not RNA binding, were examined in vivo for function at the rho-dependent IS2 and bacteriophage lambda tR1 terminators. The altered amino acids in rho are located at highly conserved residues near the beta 1 and beta 4 strands of the hydrophobic...
متن کاملDNA-dependent ATPase activity associated with vaccinia virus early transcription factor.
Vaccinia virus early transcription factor (VETF) is required for efficient expression of the early class of viral genes in vitro. The factor copurified with an ATPase activity that was stimulated by DNA. In this report we show that the ATPase remains associated with the factor upon glycerol gradient sedimentation. Under these conditions VETF sedimented at a rate of 7.6 S suggesting that it may ...
متن کاملThe role of vaccinia termination factor and cis-acting elements in vaccinia virus early gene transcription termination.
Vaccinia virus early gene transcription termination requires the virion form of the viral RNA polymerase (vRNAP), Nucleoside Triphosphate Phosphohydrolase I (NPHI), ATP, the vaccinia termination factor (VTF), and a U5NU termination signal in the nascent transcript. VTF, also the viral mRNA capping enzyme, binds U5NU, and NPHI hydrolyzes ATP to release the transcript. NPHI can release transcript...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Proceedings of the National Academy of Sciences of the United States of America
دوره 71 5 شماره
صفحات -
تاریخ انتشار 1974