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Structural basis of ECF-?-factor-dependent transcription initiation.

ABSTRACT: Extracytoplasmic (ECF) ? factors, the largest class of alternative ? factors, are related to primary ? factors, but have simpler structures, comprising only two of six conserved functional modules in primary ? factors: region 2 (?R2) and region 4 (?R4). Here, we report crystal structures of transcription initiation complexes containing Mycobacterium tuberculosis RNA polymerase (RNAP), M. tuberculosis ECF ? factor ?L, and promoter DNA. The structures show that ?R2 and ?R4 of the ECF ? factor occupy the same sites on RNAP as in primary ? factors, show that the connector between ?R2 and ?R4 of the ECF ? factor-although shorter and unrelated in sequence-follows the same path through RNAP as in primary ? factors, and show that the ECF ? factor uses the same strategy to bind and unwind promoter DNA as primary ? factors. The results define protein-protein and protein-DNA interactions involved in ECF-?-factor-dependent transcription initiation.

SUBMITTER: Lin W

PROVIDER: S-EPMC6372665 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature

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Structural basis of ECF-σ-factor-dependent transcription initiation.

Lin Wei W Mandal Sukhendu S Degen David D Cho Min Sung MS Feng Yu Y Das Kalyan K Ebright Richard H RH

Nature communications 20190212 1

Extracytoplasmic (ECF) σ factors, the largest class of alternative σ factors, are related to primary σ factors, but have simpler structures, comprising only two of six conserved functional modules in primary σ factors: region 2 (σR2) and region 4 (σR4). Here, we report crystal structures of transcription initiation complexes containing Mycobacterium tuberculosis RNA polymerase (RNAP), M. tuberculosis ECF σ factor σ<sup>L</sup>, and promoter DNA. The structures show that σR2 and σR4 of the ECF σ ...[more]

PMID: 30755604

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