1sza
From Proteopedia
The RNA polymerase II CTD in mRNA processing: beta-turn recognition and beta-spiral model
Overview
During transcription, RNA polymerase (Pol) II synthesizes eukaryotic messenger RNA. Transcription is coupled to RNA processing by the carboxy-terminal domain (CTD) of Pol II, which consists of up to 52 repeats of the sequence Tyr 1-Ser 2-Pro 3-Thr 4-Ser 5-Pro 6-Ser 7 (refs 1, 2). After phosphorylation, the CTD binds tightly to a conserved CTD-interacting domain (CID) present in the proteins Pcf11 and Nrd1, which are essential and evolutionarily conserved factors for polyadenylation-dependent and -independent 3'-RNA processing, respectively. Here we describe the structure of a Ser 2-phosphorylated CTD peptide bound to the CID domain of Pcf11. The CTD motif Ser 2-Pro 3-Thr 4-Ser 5 forms a beta-turn that binds to a conserved groove in the CID domain. The Ser 2 phosphate group does not make direct contact with the CID domain, but may be recognized indirectly because it stabilizes the beta-turn with an additional hydrogen bond. Iteration of the peptide structure results in a compact beta-spiral model of the CTD. The model suggests that, during the mRNA transcription-processing cycle, compact spiral regions in the CTD are unravelled and regenerated in a phosphorylation-dependent manner.
About this Structure
1SZA is a Single protein structure of sequence from Saccharomyces cerevisiae. Full crystallographic information is available from OCA.
Reference
Recognition of RNA polymerase II carboxy-terminal domain by 3'-RNA-processing factors., Meinhart A, Cramer P, Nature. 2004 Jul 8;430(6996):223-6. PMID:15241417 Page seeded by OCA on Sat May 3 09:18:21 2008
