1F5A

CRYSTAL STRUCTURE OF MAMMALIAN POLY(A) POLYMERASE

Summary for 1F5A

• Entry DOI: 10.2210/pdb1f5a/pdb
• Descriptor: POLY(A) POLYMERASE, MANGANESE (II) ION, 3'-DEOXYADENOSINE-5'-TRIPHOSPHATE, ... (5 entities in total)
• Functional Keywords: mrna processing, transferase, transcription, rna-binding, phosphorylation, nuclear protein, alternative splicing helical turn motif, nucleotidyl transferase catalytic domain
• Biological source: Bos taurus (cattle)
• Cellular location: Nucleus: P25500
• Total number of polymer chains: 1
• Total formula weight: 60358.12

Authors

Martin, G.,Keller, W.,Doublie, S. (deposition date: 2000-06-13, release date: 2000-09-13, Last modification date: 2024-11-06)

Primary citation

Martin, G.,Keller, W.,Doublie, S.
Crystal structure of mammalian poly(A) polymerase in complex with an analog of ATP.
EMBO J., 19:4193-4203, 2000

PubMed Abstract: In eukaryotes, polyadenylation of pre-mRNA plays an essential role in the initiation step of protein synthesis, as well as in the export and stability of mRNAs. Poly(A) polymerase, the enzyme at the heart of the polyadenylation machinery, is a template-independent RNA polymerase which specifically incorporates ATP at the 3' end of mRNA. We have solved the crystal structure of bovine poly(A) polymerase bound to an ATP analog at 2.5 A resolution. The structure revealed expected and unexpected similarities to other proteins. As expected, the catalytic domain of poly(A) polymerase shares substantial structural homology with other nucleotidyl transferases such as DNA polymerase beta and kanamycin transferase. The C-terminal domain unexpectedly folds into a compact domain reminiscent of the RNA-recognition motif fold. The three invariant aspartates of the catalytic triad ligate two of the three active site metals. One of these metals also contacts the adenine ring. Furthermore, conserved, catalytically important residues contact the nucleotide. These contacts, taken together with metal coordination of the adenine base, provide a structural basis for ATP selection by poly(A) polymerase.

PubMed: 10944102
DOI: 10.1093/emboj/19.16.4193

Experimental method

X-RAY DIFFRACTION (2.5 Å)