JBC, Vol. 250, Issue 12, 4530-4541, Jun, 1975
RNA polymerase from phage SP01-infected and uninfected Bacillus subtilis
J. J. Duffy and E. P. Geiduschek
A purification procedure for RNA polymerase from uninfected and phage
SP01-infected Bacillus subtilis is presented. The RNA polymerase purified
from B. subtilis 10 min after infection with wild type phage SP01 is
resolved into two major fractions (B, C) and one minor fraction (A) by calf
thymus DNA-cellulose chromatography. Fraction C is indistinguishable from
RNA polymerase from uninfected cells with respect to transcription
specificity (both before and after phosphocellulose chromatography).
Fraction B yields, on subsequent phosphocellulose chromatography, an enzyme
(B-P) whose properties distinguish it from the host RNA polymerase. Enzyme
B-P preferentially transcribes SP01 DNA and selectively forms rapidly
initiating complexes with SP01 DNA but not with heterologous DNA. The SP01
RNA synthesized by Enzyme B-P includes, as previously reported, a large
proportion of asymmetrical middle viral RNA. Host RNA polymerase holoenzyme
synthesizes asymmetrical early viral RNA, while host core polymerase
synthesizes symmetrical RNA that is complementary to early, middle, and
late in vivo viral RNA and contains a preponderance of antimessenger. The
subunit composition of Enzyme B-P is identical to host core polymerase with
respect to the beta,beta', and alpha subunits and two additional components
of mr equals 9,500 and 11,000 that we observe in all preparations of RNA
polymerase. In addition, Enzyme B-P has two subunits of mr equals 13,000
and 28,000, which are synthesized after phage infection. On heterologous
template, Enzyme B-P and host core polymerase have comparable activities.
On these templates, addition of host initiation factor, sigma, restores
full activity to Enzyme B-P as well as to host core polymerase. Sigma also
modifies the activity of Enzyme B-P on SP01 DNA, restoring some
asymmetrical early RNA transcription while retaining some asymmetrical
middle RNA transcription.