1TLH

T4 AsiA bound to sigma70 region 4

Summary for 1TLH

• Entry DOI: 10.2210/pdb1tlh/pdb
• Related: 1TKV 1TL6
• Descriptor: 10 kDa anti-sigma factor, RNA polymerase sigma factor rpoD (2 entities in total)
• Functional Keywords: anti-sigma, sigma70, rna polymerase, transcription
• Biological source: Enterobacteria phage T4; More
• Cellular location: Cytoplasm (Potential): P00579
• Total number of polymer chains: 2
• Total formula weight: 19924.58

Authors

Lambert, L.J.,Wei, Y.,Schirf, V.,Demeler, B.,Werner, M.H. (deposition date: 2004-06-09, release date: 2004-11-23, Last modification date: 2024-05-01)

Primary citation

Lambert, L.J.,Wei, Y.,Schirf, V.,Demeler, B.,Werner, M.H.
T4 AsiA blocks DNA recognition by remodeling sigma(70) region 4
Embo J., 23:2952-2962, 2004

PubMed Abstract: Bacteriophage T4 AsiA is a versatile transcription factor capable of inhibiting host gene expression as an 'anti-sigma' factor while simultaneously promoting gene-specific expression of T4 middle genes in conjunction with T4 MotA. To accomplish this task, AsiA engages conserved region 4 of Eschericia coli sigma70, blocking recognition of most host promoters by sequestering the DNA-binding surface at the AsiA/sigma70 interface. The three-dimensional structure of an AsiA/region 4 complex reveals that the C-terminal alpha helix of region 4 is unstructured, while four other helices adopt a completely different conformation relative to the canonical structure of unbound region 4. That AsiA induces, rather than merely stabilizes, this rearrangement can be realized by comparison to the homologous structures of region 4 solved in a variety of contexts, including the structure of Thermotoga maritima sigmaA region 4 described herein. AsiA simultaneously occupies the surface of region 4 that ordinarily contacts core RNA polymerase (RNAP), suggesting that an AsiA-bound sigma70 may also undergo conformational changes in the context of the RNAP holoenzyme.

PubMed: 15257291
DOI: 10.1038/sj.emboj.7600312

Experimental method

SOLUTION NMR