Structural highlights
Function
SYMPK_HUMAN Scaffold protein that functions as a component of a multimolecular complex involved in histone mRNA 3'-end processing. Specific component of the tight junction (TJ) plaque, but might not be an exclusively junctional component. May have a house-keeping rule. Is involved in pre-mRNA polyadenylation. Enhances SSU72 phosphatase activity.[1] [2]
Publication Abstract from PubMed
Ssu72, an RNA polymerase II C-terminal domain (CTD) phospho-Ser5 (pSer5) phosphatase, was recently reported to have pSer7 phosphatase activity as well. We report here the crystal structure of a ternary complex of the N-terminal domain of human symplekin, human Ssu72, and a 10-mer pSer7 CTD peptide. Surprisingly, the peptide is bound in the Ssu72 active site with its backbone running in the opposite direction compared with a pSer5 peptide. The pSer7 phosphatase activity of Ssu72 is approximately 4000-fold lower than its pSer5 phosphatase activity toward a peptide substrate, consistent with the structural observations.
An unexpected binding mode for a Pol II CTD peptide phosphorylated at Ser7 in the active site of the CTD phosphatase Ssu72.,Xiang K, Manley JL, Tong L Genes Dev. 2012 Oct 15;26(20):2265-70. doi: 10.1101/gad.198853.112. PMID:23070812[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Kolev NG, Steitz JA. Symplekin and multiple other polyadenylation factors participate in 3'-end maturation of histone mRNAs. Genes Dev. 2005 Nov 1;19(21):2583-92. Epub 2005 Oct 17. PMID:16230528 doi:10.1101/gad.1371105
- ↑ Xiang K, Nagaike T, Xiang S, Kilic T, Beh MM, Manley JL, Tong L. Crystal structure of the human symplekin-Ssu72-CTD phosphopeptide complex. Nature. 2010 Sep 22. PMID:20861839 doi:10.1038/nature09391
- ↑ Xiang K, Manley JL, Tong L. An unexpected binding mode for a Pol II CTD peptide phosphorylated at Ser7 in the active site of the CTD phosphatase Ssu72. Genes Dev. 2012 Oct 15;26(20):2265-70. doi: 10.1101/gad.198853.112. PMID:23070812 doi:http://dx.doi.org/10.1101/gad.198853.112
