3KYH

Saccharomyces cerevisiae Cet1-Ceg1 capping apparatus

Summary for 3KYH

• Entry DOI: 10.2210/pdb3kyh/pdb
• Descriptor: mRNA-capping enzyme subunit beta, mRNA-capping enzyme subunit alpha (2 entities in total)
• Functional Keywords: capping, rna, 5' modification, triphosphatase, guanylyltransferase, complex, hydrolase, mrna capping, mrna processing, nucleus, phosphoprotein, gtp-binding, nucleotide-binding, nucleotidyltransferase, transferase, protein binding
• Biological source: Saccharomyces cerevisiae (brewer's yeast,lager beer yeast,yeast); More
• Cellular location: Nucleus: O13297 Q01159
• Total number of polymer chains: 4
• Total formula weight: 177111.19

Authors

Lima, C.D. (deposition date: 2009-12-06, release date: 2010-02-16, Last modification date: 2024-02-21)

Primary citation

Gu, M.,Rajashankar, K.R.,Lima, C.D.
Structure of the Saccharomyces cerevisiae Cet1-Ceg1 mRNA Capping Apparatus.
Structure, 18:216-227, 2010

PubMed Abstract: The 5' guanine-N7 cap is the first cotranscriptional modification of messenger RNA. In Saccharomyces cerevisiae, the first two steps in capping are catalyzed by the RNA triphosphatase Cet1 and RNA guanylyltransferase Ceg1, which form a complex that is directly recruited to phosphorylated RNA polymerase II (RNAP IIo), primarily via contacts between RNAP IIo and Ceg1. A 3.0 A crystal structure of Cet1-Ceg1 revealed a 176 kDa heterotetrameric complex composed of one Cet1 homodimer that associates with two Ceg1 molecules via interactions between the Ceg1 oligonucleotide binding domain and an extended Cet1 WAQKW amino acid motif. The WAQKW motif is followed by a flexible linker that would allow Ceg1 to achieve conformational changes required for capping while maintaining interactions with both Cet1 and RNAP IIo. The impact of mutations as assessed through genetic analysis in S. cerevisiae is consonant with contacts observed in the Cet1-Ceg1 structure.

PubMed: 20159466
DOI: 10.1016/j.str.2009.12.009

Experimental method

X-RAY DIFFRACTION (3 Å)