For the microarray experiment, RNA was isolated from two
independent cultures each of wild-type (MG1655; KW489) or 6S
RNA null (ssrS3; KW490) cells grown at 37 uC for 16 h after dilution
to OD600 0.05 into RDM. RNA samples were sent to Nimblegen for
analysis using the standard protocol for measuring mRNA levels on E.
coli expression microarrays (Design T183333 60-mer, E. coli K-12).
The full dataset will be published elsewhere (A. T. Cavanagh & K. M.
Wassarman, unpublished data).