Magnesium-Induced Nucleophile Activation in the Guanylyltransferase mRNA Capping Enzyme
نویسندگان
چکیده
منابع مشابه
Mechanism of mRNA capping by vaccinia virus guanylyltransferase: characterization of an enzyme--guanylate intermediate.
Vaccinia virus RNA guanylyltransferase catalyzes the transfer of GMP from GTP to the 5'-triphosphate or diphosphate terminus of RNA to generate the cap structure G(5')ppp(5')N-. The guanylylation reaction consists of a series of at least two partial reactions: (i) GTP + E in equilibrium E-pG + PPi, (ii) E-pG + (p)ppNpNpN- leads to GpppNpNpN- + E. Inthe first of these, GTP reacts with capping en...
متن کاملMammalian capping enzyme complements mutant Saccharomyces cerevisiae lacking mRNA guanylyltransferase and selectively binds the elongating form of RNA polymerase II.
5'-Capping is an early mRNA modification that has important consequences for downstream events in gene expression. We have isolated mammalian cDNAs encoding capping enzyme. They contain the sequence motifs characteristic of the nucleotidyl transferase superfamily. The predicted mouse and human enzymes consist of 597 amino acids and are 95% identical. Mouse cDNA directed synthesis of a guanylyla...
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The Semliki Forest virus (SFV) replicase protein nsP1 has methyltransferase (MT) and guanylyltransferase-like (GT) activities, which are involved in the capping of viral mRNAs. MT catalyzes the transfer of the methyl group from S-adenosylmethionine (AdoMet) to position 7 of GTP, and this reaction is followed by GT-catalyzed formation of the covalent complex m7GMP-nsP1. These reactions are virus...
متن کاملSubstrate Induced Population Shifts and Stochastic Gating in the PBCV-1 mRNA Capping Enzyme
The 317 residue PBCV-1 mRNA capping enzyme catalyzes the second enzymatic reaction in the formation of an N-7-methyl-GMP cap on the 5'-end of the nascent mRNA. It is composed of two globular domains bound by a short flexible peptide linker, which have been shown to undergo opening and closing events. The small size and experimentally demonstrated domain mobility make the PBCV-1 capping enzyme a...
متن کاملActive site localization in a viral mRNA capping enzyme.
Capping of reovirus mRNAs is catalyzed by a guanylyltransferase that corresponds to virion structural polypeptide lambda 2. It forms a phosphoamide linked enzyme-pG covalent complex as an intermediate in the capping reaction. The nucleotide attachment site on lambda 2 was localized to a region between amino acids 213 and 269 by incubating virus particles with [alpha-32P]GTP followed by proteoly...
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ژورنال
عنوان ژورنال: Biochemistry
سال: 2012
ISSN: 0006-2960,1520-4995
DOI: 10.1021/bi301224b