Cazdobacter crescentus RNA Polymerase PURIFICATION
نویسندگان
چکیده
Caulobacter crescentus RNA polymerase holoenzyme and core enzyme have been separated by chromatography on denatured DNA-cellulose and purified by phosphocellulose chromatography. In order to assess the functional role of the putative C. crescentus CT subunit, the enzymes were compared to Escherichia coli holoenzyme and core RNA polymerases, and the transcription of various DNA templates by C. crescentus core polymerase with E. coli was examined. 6. crescentus and E. coli RNA polymerases differed with respect to subunit molecular weight and degree of immunologic cross-reactivity. Despite these differences, the E. coli cr subunit partially stimulated the transcription of E. coli phage T7 or T2 DNA templates by C. crescentus core enzyme. The presence of the (T subunit influenced both the specificity of nucleoside triphosphate incorporation at the 5’ terminus of the RNA chain and the selective strand transcription of phage T7 DNA. Evidence that the C. crescentus core polymerase and (T subunit is functionally analogous to the E. coli core polymerase-u subunit interaction includes the following. (a) Addition of E. coli (r to the C. crescentus core polymerase, but not to the C. crescentus holoenzyme, preferentially stimulated transcription of E. coli DNA templates. (b) C. crescentus holoenzyme, but not core polymerase, formed open binary complexes with template DNA. (c) The interaction of the q subunit with the core polymerase influenced both the specificity of 5’-terminal ribonucleoside triphosphate incorporation and the asymmetric transcription of phage T7 DNA template.
منابع مشابه
Purification, characterization, and reconstitution of DNA-dependent RNA polymerases from Caulobacter crescentus.
Cell differentiation in the Caulobacter crescentus cell cycle requires differential gene expression that is regulated primarily at the transcriptional level. Until now, however, a defined in vitro transcription system for the biochemical study of developmentally regulated transcription factors had not been available in this bacterium. We report here the purification of C. crescentus RNA polymer...
متن کاملCaulobacter crescentus RNA polymerase. Purification and characterization of holoenzyme and core polymerase.
متن کامل
Deoxyribonucleic acid-dependent ribonucleic acid polymerase of Caulobacter crescentus.
Deoxyribonucleic acid-dependent ribonucleic acid (RNA) polymerase (EC 2.7.7.6) was purified from the dimorphic bacterium Caulobacter crescentus at three stages in development. Enzyme from pure populations of stalked cells, as well as populations enriched in swarmer and predivisional cells, appeared identical in subunit structure and template requirements. The molecular weights of the enzyme sub...
متن کاملPurification and properties of initiation factor IF-3 from Caulobacter crescentus.
A five-step procedure is described for the purification to homogeneity of initiation factor IF-3 from ribosomal washes of CauZobacter crescentus. The protein, C-IF-J, has a molecular weight of 24,000 to 25,000 and seems to consist of a single polypeptide chain. It has three in vitro activities. (a) It promotes ribosomal binding of N-formyl methionyl transfer RNA directed by phage messengers ; (...
متن کاملCaulobacter crescentus CdnL is a non-essential RNA polymerase-binding protein whose depletion impairs normal growth and rRNA transcription
CdnL is an essential RNA polymerase (RNAP)-binding activator of rRNA transcription in mycobacteria and myxobacteria but reportedly not in Bacillus. Whether its function and mode of action are conserved in other bacteria thus remains unclear. Because virtually all alphaproteobacteria have a CdnL homolog and none of these have been characterized, we studied the homolog (CdnLCc) of the model alpha...
متن کامل