In:
Proteins: Structure, Function, and Bioinformatics, Wiley, Vol. 88, No. 1 ( 2020-01), p. 69-81
Abstract:
In class II transcription activation, the transcription factor normally binds to the promoter near the −35 position and contacts the domain 4 of σ factors (σ 4 ) to activate transcription. However, σ 4 of σ 70 appears to be poorly folded on its own. Here, by fusing σ 4 with the RNA polymerase β‐flap‐tip‐helix, we constructed two σ 4 chimera proteins, one from σ 70 and another from σ S of Klebsiella pneumoniae . The two chimera proteins well folded into a monomeric form with strong binding affinities for −35 element DNA. Determining the crystal structure of in complex with −35 element DNA revealed that adopts a similar structure as σ 4 in the Escherichia coli RNA polymerase σ S holoenzyme and recognizes −35 element DNA specifically by several conserved residues from the helix‐turn‐helix motif. By using nuclear magnetic resonance (NMR), was demonstrated to recognize −35 element DNA similar to . Carr‐Purcell‐Meiboom‐Gill relaxation dispersion analyses showed that the N‐terminal helix and the β‐flap‐tip‐helix of have a concurrent transient α‐helical structure and DNA binding reduced the slow dynamics on . Finally, only was shown to interact with the response regulator PmrA and its promoter DNA. The chimera proteins are capable of −35 element DNA recognition and can be used for study with transcription factors or other factors that interact with domain 4 of σ factors.
Type of Medium:
Online Resource
ISSN:
0887-3585
,
1097-0134
Language:
English
Publisher:
Wiley
Publication Date:
2020
detail.hit.zdb_id:
1475032-6
SSG:
12
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