Table 1.

RNA polymerase content and activity in large cells, small cells, and minicells of strain χ925

Cell typeaProtein concnb(mg/ml)αp c(%)RNA polymerase activity
cpm/2 μld (%)cpm/μg of proteine (%)cpm/μg of polymerasef (%)
Large15.51.001,441 (100)46.4 (100)4,640 (100)
Small9.20.92859 (69)46.6 (100)5,065 (109)
Mini2.60.171 (0.1)0.2 (0.1)118 (2.5)
  • a Minicell, small-cell, and large-cell lysates were prepared as described in Materials and Methods.

  • b A portion of each lysate was used to determine the protein concentration.

  • c Another portion of each lysate was subjected to SDS-gel electrophoresis (see Materials and Methods) (Fig. 3), and αp (percentage of total protein that is RNA polymerase protein) was determined.

  • d Each value is the average (minus blank) of two assays on T5 DNA after KCl treatment (see Materials and Methods for details). The values in parentheses were calculated by setting the large-cell value to 100%.

  • e The RNA polymerase activity per microgram of total protein is the quotient of the values in the columns indicated by footnotes d and b, divided by 2 (microliters per assay).

  • f The RNA polymerase activity per microgram of RNA polymerase is the quotient of the values in the columns indicated by footnotes e and c.