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Crystal structure of the human symplekin-Ssu72-CTD phosphopeptide complex

Symplekin (Pta1 in yeast) is a scaffold in the large protein complex that is required for 3′-end cleavage and polyadenylation of eukaryotic messenger RNA precursors (pre-mRNAs) 1–4, and also participates in transcription initiation and termination by RNA polymerase II (Pol II) 5,6. Symplekin mediate...

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Autores principales: Xiang, Kehui, Nagaike, Takashi, Xiang, Song, Kilic, Turgay, Beh, Maia M., Manley, James L., Tong, Liang
Formato: Texto
Lenguaje:English
Publicado: 2010
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3038789/
https://www.ncbi.nlm.nih.gov/pubmed/20861839
http://dx.doi.org/10.1038/nature09391
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author Xiang, Kehui
Nagaike, Takashi
Xiang, Song
Kilic, Turgay
Beh, Maia M.
Manley, James L.
Tong, Liang
author_facet Xiang, Kehui
Nagaike, Takashi
Xiang, Song
Kilic, Turgay
Beh, Maia M.
Manley, James L.
Tong, Liang
author_sort Xiang, Kehui
collection PubMed
description Symplekin (Pta1 in yeast) is a scaffold in the large protein complex that is required for 3′-end cleavage and polyadenylation of eukaryotic messenger RNA precursors (pre-mRNAs) 1–4, and also participates in transcription initiation and termination by RNA polymerase II (Pol II) 5,6. Symplekin mediates interactions among many different proteins in this machinery 1,2,7–9, although the molecular basis for its function is not known. Here we report the crystal structure at 2.4 Å resolution of the N-terminal domain (residues 30–340) of human symplekin (Symp-N) in a ternary complex with the Pol II C-terminal domain (CTD) Ser(5) phosphatase Ssu72 7,10–17 and a CTD Ser(5) phosphopeptide. The N-terminal domain of symplekin has the ARM or HEAT fold, with seven pairs of anti-parallel α-helices arranged in the shape of an arc. The structure of Ssu72 has some similarity to that of low-molecular-weight phosphotyrosine protein phosphatase 18,19, although Ssu72 has a unique active site landscape as well as extra structural features at the C-terminus that is important for interaction with symplekin. Ssu72 is bound to the concave face of symplekin, and engineered mutations in this interface can abolish interactions between the two proteins. The CTD peptide is bound in the active site of Ssu72, unexpectedly with the pSer(5)-Pro(6) peptide bond in the cis configuration, which contrasts with all other known CTD peptide conformations 20,21. While the active site of Ssu72 is about 25 Å away from the interface with symplekin, we found that the symplekin N-terminal domain stimulates Ssu72 CTD phosphatase activity in vitro. Furthermore, the N-terminal domain of symplekin inhibits polyadenylation in vitro, but importantly only when coupled to transcription. As catalytically active Ssu72 overcomes this inhibition, our results demonstrate a role for mammalian Ssu72 in transcription-coupled pre-mRNA 3′-end processing.
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spelling pubmed-30387892011-04-07 Crystal structure of the human symplekin-Ssu72-CTD phosphopeptide complex Xiang, Kehui Nagaike, Takashi Xiang, Song Kilic, Turgay Beh, Maia M. Manley, James L. Tong, Liang Nature Article Symplekin (Pta1 in yeast) is a scaffold in the large protein complex that is required for 3′-end cleavage and polyadenylation of eukaryotic messenger RNA precursors (pre-mRNAs) 1–4, and also participates in transcription initiation and termination by RNA polymerase II (Pol II) 5,6. Symplekin mediates interactions among many different proteins in this machinery 1,2,7–9, although the molecular basis for its function is not known. Here we report the crystal structure at 2.4 Å resolution of the N-terminal domain (residues 30–340) of human symplekin (Symp-N) in a ternary complex with the Pol II C-terminal domain (CTD) Ser(5) phosphatase Ssu72 7,10–17 and a CTD Ser(5) phosphopeptide. The N-terminal domain of symplekin has the ARM or HEAT fold, with seven pairs of anti-parallel α-helices arranged in the shape of an arc. The structure of Ssu72 has some similarity to that of low-molecular-weight phosphotyrosine protein phosphatase 18,19, although Ssu72 has a unique active site landscape as well as extra structural features at the C-terminus that is important for interaction with symplekin. Ssu72 is bound to the concave face of symplekin, and engineered mutations in this interface can abolish interactions between the two proteins. The CTD peptide is bound in the active site of Ssu72, unexpectedly with the pSer(5)-Pro(6) peptide bond in the cis configuration, which contrasts with all other known CTD peptide conformations 20,21. While the active site of Ssu72 is about 25 Å away from the interface with symplekin, we found that the symplekin N-terminal domain stimulates Ssu72 CTD phosphatase activity in vitro. Furthermore, the N-terminal domain of symplekin inhibits polyadenylation in vitro, but importantly only when coupled to transcription. As catalytically active Ssu72 overcomes this inhibition, our results demonstrate a role for mammalian Ssu72 in transcription-coupled pre-mRNA 3′-end processing. 2010-09-22 2010-10-07 /pmc/articles/PMC3038789/ /pubmed/20861839 http://dx.doi.org/10.1038/nature09391 Text en Users may view, print, copy, download and text and data- mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use: http://www.nature.com/authors/editorial_policies/license.html#terms
spellingShingle Article
Xiang, Kehui
Nagaike, Takashi
Xiang, Song
Kilic, Turgay
Beh, Maia M.
Manley, James L.
Tong, Liang
Crystal structure of the human symplekin-Ssu72-CTD phosphopeptide complex
title Crystal structure of the human symplekin-Ssu72-CTD phosphopeptide complex
title_full Crystal structure of the human symplekin-Ssu72-CTD phosphopeptide complex
title_fullStr Crystal structure of the human symplekin-Ssu72-CTD phosphopeptide complex
title_full_unstemmed Crystal structure of the human symplekin-Ssu72-CTD phosphopeptide complex
title_short Crystal structure of the human symplekin-Ssu72-CTD phosphopeptide complex
title_sort crystal structure of the human symplekin-ssu72-ctd phosphopeptide complex
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3038789/
https://www.ncbi.nlm.nih.gov/pubmed/20861839
http://dx.doi.org/10.1038/nature09391
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