Article
- The EMBO Journal (2000) 19, 1555 - 1566
- doi:10.1093/emboj/19.7.1555
The Escherichia coli RNA polymerase 
subunit linker: length requirements for transcription activation at CRP-dependent promoters
Wenmao Meng1, Nigel J. Savery2, Stephen J.W. Busby3 and Mark S. Thomas1
- Division of Molecular and Genetic Medicine, University of Sheffield Medical School, Sheffield S10 2RX, UK
- Department of Biochemistry, University of Bristol, School of Medical Sciences, University Walk, Bristol BS8 1TD, UK
- School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK
Correspondence to:
Mark S. Thomas, E-mail: m.s.thomas@sheffield.ac.uk
Received 7 January 2000; Accepted 10 February 2000; Revised 10 February 2000
Abstract
The C-terminal domain of the Escherichia coli RNA polymerase 
subunit (CTD) plays a key role in transcription initiation at many activator-dependent promoters. This domain is connected to the N-terminal domain by an unstructured linker, which is proposed to confer a high degree of mobility on CTD. To investigate the role of this linker in transcription activation we tested the effect of altering the linker length on promoters dependent on the cyclic AMP receptor protein (CRP). Short deletions within the linker decrease CRP-dependent transcription at a Class I promoter while increasing the activity of a Class II promoter. Linker extension impairs CRP-dependent transcription from both promoters, with short extensions exerting a more marked effect on the Class II promoter. Activation at both classes of promoter was shown to remain dependent upon activating region 1 of CRP. These results show that the response to CRP of RNA polymerase containing linker-modified subunits is class specific. These observations have important implications for the architecture of transcription initiation complexes at CRP-dependent promoters.
Keywords:
- subunit,
- cyclic AMP receptor protein,
- inter-domain linker,
- RNA polymerase,
- transcription activation
