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Tfb6, a previously unidentified subunit of the general transcription factor TFIIH, facilitates dissociation of Ssl2 helicase after transcription initiation.

ABSTRACT: General transcription factor TFIIH, previously described as a 10-subunit complex, is essential for transcription and DNA repair. An eleventh subunit now identified, termed Tfb6, exhibits 45% sequence similarity to human nuclear mRNA export factor 5. Tfb6 dissociates from TFIIH as a heterodimer with the Ssl2 subunit, a DNA helicase that drives promoter melting for the initiation of transcription. Tfb6 does not, however, dissociate Ssl2 from TFIIH in the context of a fully assembled transcription preinitiation complex. Our findings suggest a dynamic state of Ssl2, allowing its engagement in multiple cellular processes.

SUBMITTER: Murakami K

PROVIDER: S-EPMC3323989 | biostudies-literature | 2012 Mar

REPOSITORIES: biostudies-literature

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Tfb6, a previously unidentified subunit of the general transcription factor TFIIH, facilitates dissociation of Ssl2 helicase after transcription initiation.

Murakami Kenji K Gibbons Brian J BJ Davis Ralph E RE Nagai Shigeki S Liu Xin X Robinson Philip J J PJ Wu Tinghe T Kaplan Craig D CD Kornberg Roger D RD

Proceedings of the National Academy of Sciences of the United States of America 20120312 13

General transcription factor TFIIH, previously described as a 10-subunit complex, is essential for transcription and DNA repair. An eleventh subunit now identified, termed Tfb6, exhibits 45% sequence similarity to human nuclear mRNA export factor 5. Tfb6 dissociates from TFIIH as a heterodimer with the Ssl2 subunit, a DNA helicase that drives promoter melting for the initiation of transcription. Tfb6 does not, however, dissociate Ssl2 from TFIIH in the context of a fully assembled transcription ...[more]

PMID: 22411836

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