Literatur vom gleichen Autor/der gleichen Autor*in
plus bei Google Scholar

Bibliografische Daten exportieren
 

Biochemical and structural insights into substrate binding and catalytic mechanism of mammalian poly(A) polymerase

Titelangaben

Martin, Georges ; Möglich, Andreas ; Keller, Walter ; Doublié, Sylvie:
Biochemical and structural insights into substrate binding and catalytic mechanism of mammalian poly(A) polymerase.
In: Journal of Molecular Biology. Bd. 341 (2004) Heft 4 . - S. 911-925.
ISSN 0022-2836
DOI: https://doi.org/10.1016/j.jmb.2004.06.047

Abstract

Polyadenylation of messenger RNA precursors is an essential process in eukaryotes. Poly(A) polymerase (PAP), a member of the nucleotidyltransferase family that includes DNA polymerase beta, incorporates ATP at the 3' end of mRNAs in a template-independent manner. Although the structures of mammalian and yeast PAPs are known, their mechanism of ATP selection has remained elusive. In a recent bovine PAP structure complexed with an analog of ATP and Mn2+, strictly conserved residues interact selectively with the adenine base, but the nucleotide was found in a "non-productive" conformation. Here we report a second bovine crystal structure, obtained in the presence of Mg2+, where 3'-dATP adopts a "productive" conformation similar to that seen in yeast PAP or DNA polymerase beta. Mutational analysis and activity assays with ATP analogs suggest a role in catalysis for one of the two adenine-binding sites revealed by our structural data. The other site might function to prevent futile hydrolysis of ATP. In order to investigate the role of metals in catalysis we performed steady state kinetics experiments under distributive polymerization conditions. These tests suggest a sequential random mechanism in vitro in the presence of ATP and RNA, without preference for a particular order of binding of the two substrates. In vivo, however, where polyadenylation is processive and the primer does not dissociate from the enzyme, an ordered mechanism with the primer as the leading substrate is more likely.

Weitere Angaben

Publikationsform: Artikel in einer Zeitschrift
Begutachteter Beitrag: Ja
Zusätzliche Informationen: PubMed-ID: 15328606
Institutionen der Universität: Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften > Fachgruppe Chemie > Lehrstuhl Biochemie > Lehrstuhl Biochemie II - Photobiochemie - Univ.-Prof. Dr. Andreas Möglich
Fakultäten
Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften
Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften > Fachgruppe Chemie
Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften > Fachgruppe Chemie > Professur Biochemie
Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften > Fachgruppe Chemie > Lehrstuhl Biochemie
Titel an der UBT entstanden: Nein
Themengebiete aus DDC: 500 Naturwissenschaften und Mathematik > 540 Chemie
Eingestellt am: 20 Mai 2015 08:40
Letzte Änderung: 08 Jul 2022 13:52
URI: https://eref.uni-bayreuth.de/id/eprint/13617