Loss of sigma-factor of RNA polymerase of XXXX . oryzae during phage Xp10 infection.

@entity1025 @entity3281 @entity8816 @entity17847 @entity1129
Ten min after infection of @entity17847 . oryzae by phage Xp10, a sharp decrease in the activity of the host RNA polymerase was observed. Host RNA polymerase from phage-infected and uninfected cells was purified, and their properties were compared. The enzyme from uninfected cells contained four polypeptides with Mr = 155,000, 155,000, 93,000, and 37,000, respectively, and assembled with a stoichiometry of alpha 2 beta beta' sigma. The enzyme from infected cells lacked the sigma-subunit. The enzyme from uninfected cells utilized Xp10 DNA and poly[d( @entity1129 )] as templates, the enzyme from phage-infected cells failed to transcribe Xp10 DNA, but retained the ability to transcribe poly( @entity1129 ). The regions of the Xp10 genome transcribed by the two enzymes were also investigated. The enzyme from uninfected cells transcribed the leftmost 25-30% of the Xp10 genome. The enzyme from phage-infected cells also transcribed the same region, but the enzyme activity was very low. Other properties such as (a) the response to RNA polymerase inhibitors, (b) the effect of @entity8816 , (c) the requirement of @entity1025 and @entity3281 , and (d) the optimum temperature and pH of the two enzymes were very similar.
