The regulation of transcription initiation in bacteria.

INTRODUCTION ..................................................................................... 355 PROMOTER ST UCTURE ......................................................................... 356 THE REGULATION F E~TM TRANSCRIPTION I ITIATION ............................ 360 Negative Regulation of Transcription Initiation ............................................. 361 Positive Regulation of Transcription Initiation .............................................. 363 DNA Topology Regulation of Transcription Initiation ...................................... 365 DNA Modification and the Regulation of Gene Expression ............................... 366 MODIFICATION OF HOLOENZYME STRUCTURE AND THE REGULATION OF GENE XPRESSION ................................................................... 366 E. coil ~r7° .......................................................................................... 367 The Heat Shock Response and ~r~2 ............................................................. 368 The E. coli ntrA (glnF) Protein: Another Sigma Factor ................................... 370 B. subtilis Sporulation ........................................................................... 371 Sigma Factors in B. subtilis .................................................................... 372 Phage-Encoded Sigma Factors ................................................................. 376 Conservation of Structure Among Sigma Factors ........................................... 377 Modulation of Sigma Factor Use .............................................................. 377 Role of Sigma in Promoter Recognition ...................................................... 379