Purification and subunit characterization of Rhizobium meliloti RNA polymerase.
AUTOR(ES)
Nielsen, B L
RESUMO
The RNA polymerase of the symbiotic, nitrogen-fixing bacterium Rhizobium meliloti was purified, and its subunit composition was determined. The cells were disrupted in the presence of protease inhibitors, and holoenzyme fractions were purified by fractionation by using DEAE-cellulose and DNA-agarose chromatography. The core polymerase was purified by additional chromatography on phosphocellulose. The subunit structure is beta prime (155,000 molecular weight), beta (151,000), alpha (43,000), and sigma (93,000), with an additional polypeptide of 29,000 molecular weight, which we have designated tau, found associated with both core and holoenzyme fractions. The measured stoichiometry of the holoenzyme complex was found to be 2 alpha:1 beta':1 beta:0.7 sigma:1 tau. The 93,000 molecular-weight protein subunit was identified as the sigma subunit based upon stimulation of specific transcription in assays with reconstituted polymerase.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=218898Documentos Relacionados
- Rapid and simple purification of T7 RNA polymerase.
- Isolation and characterization of transducing phage coding for sigma subunit of Escherichia coli RNA polymerase.
- Purification and characterization of poliovirus polypeptide 3CD, a proteinase and a precursor for RNA polymerase.
- Purification and characterization of varicella-zoster virus-induced DNA polymerase.
- Expression, purification, and properties of recombinant encephalomyocarditis virus RNA-dependent RNA polymerase.
