3RTX

Crystal structure of mammalian capping enzyme (Mce1) and Pol II CTD complex

Summary for 3RTX

• Entry DOI: 10.2210/pdb3rtx/pdb
• Related: 1I9S 1I9T
• Descriptor: mRNA-capping enzyme, RNA Polymerase II C-terminal domain, GUANINE, ... (4 entities in total)
• Functional Keywords: guanylyltransferase, rna polymerase ii ctd, lysyl-n-gmp, nucleus, mrna capping, transferase
• Biological source: Mus musculus (mouse); More
• Cellular location: Nucleus: O55236
• Total number of polymer chains: 3
• Total formula weight: 81397.20

Authors

Ghosh, A.,Lima, C.D. (deposition date: 2011-05-04, release date: 2011-06-29, Last modification date: 2024-10-30)

Primary citation

Ghosh, A.,Shuman, S.,Lima, C.D.
Structural insights to how mammalian capping enzyme reads the CTD code.
Mol.Cell, 43:299-310, 2011

PubMed Abstract: Physical interaction between the phosphorylated RNA polymerase II carboxyl-terminal domain (CTD) and cellular capping enzymes is required for efficient formation of the 5' mRNA cap, the first modification of nascent mRNA. Here, we report the crystal structure of the RNA guanylyltransferase component of mammalian capping enzyme (Mce) bound to a CTD phosphopeptide. The CTD adopts an extended β-like conformation that docks Tyr1 and Ser5-PO(4) onto the Mce nucleotidyltransferase domain. Structure-guided mutational analysis verified that the Mce-CTD interface is a tunable determinant of CTD binding and stimulation of guanylyltransferase activity, and of Mce function in vivo. The location and composition of the CTD binding site on mammalian capping enzyme is distinct from that of a yeast capping enzyme that recognizes the same CTD primary structure. Thus, capping enzymes from different taxa have evolved different strategies to read the CTD code.

PubMed: 21683636
DOI: 10.1016/j.molcel.2011.06.001

Experimental method

X-RAY DIFFRACTION (2.81 Å)