EC Number   |
General Information |
Reference |
|---|
   2.7.7.79 | evolution |
implications for the evolution of eukaryotic Thg1 from a family of ancestral promiscuous RNA repair enzymes to the highly selective enzymes needed for their essential function in tRNAHis maturation. The HisRS requirement for Gx031 is a conserved feature throughout all domains of life, but bacteria and eukaryotes have evolved different mechanisms of incorporating the additionalx031 nucleotide into tRNAHis. Most eukaryotes studied to date incorporate G-1 posttranscriptionally to the processed 5' end of tRNAHis. This posttranscriptional addition of G-1 is performed by the tRNAHis guanylyltransferase (Thg1). Eukaryotic Thg1 enzymes are strictly specific for tRNAHis, and this specificity is accomplished by recognition of the tRNAHis GUG anticodon |
761511 |
| 2.7.7.79 | evolution |
the active site moiety of ScThg1 is highly conserved among members of the Thg1 family, comparisons of structure ana binding modes, overview |
-, 760482 |
| 2.7.7.79 | evolution |
the archaeal type Thg1, which includes most archaeal and bacterial Thg1 enzymes, is phylogenetically distant from eukaryotic Thg1 |
-, 762377 |
| 2.7.7.79 | evolution |
the archaeal type Thg1, which includes most archaeal and bacterial Thg1 enzymes, is phylogenetically distant from eukaryotic Thg1. Thg1 is evolutionarily related to canonical 5'-3' forward polymerases but catalyzes reverse 3'-5' polymerization. Similar to its forward polymerase counterparts, Thg1 encodes the conserved catalytic palm domain and fingers domain. Naturally occurring minimal Thg1 enzyme from Ignicoccus hospitalis (IhThg1), which lacks parts of the conserved fingers domain, is catalytically active. And adds all four natural nucleotides to RNA substrates. The entire fingers domain of Methanosarcina acetivorans Thg1 and Pyrobaculum aerophilum Thg1 (PaThg1) is dispensable for enzymatic activity |
-, 762377 |
| 2.7.7.79 | evolution |
the archaeal type Thg1, which includes most archaeal and bacterial Thg1 enzymes, is phylogenetically distant from eukaryotic Thg1. Thg1 is evolutionarily related to canonical 5'-3' forward polymerases but catalyzes reverse 3'-5' polymerization. Similar to its forward polymerase counterparts, Thg1 encodes the conserved catalytic palm domain and fingers domain. Naturally occurring minimal Thg1 enzyme from Ignicoccus hospitalis (IhThg1), which lacks parts of the conserved fingers domain, is catalytically active. And adds all four natural nucleotides to RNA substrates. The entire fingers domain of Methanosarcina acetivorans Thg1 and Pyrobaculum aerophilum Thg1 (PaThg1) is dispensable for enzymatic activity. Naturally occurring Thg1 enzyme from Ignicoccus hospitalis (IhThg1) lacks several sections of the protein, and aligns poorly with other Thg1 sequences, it is identified in a large Thg1 phylogenetic analysis |
762377 |
| 2.7.7.79 | evolution |
the tRNAHis guanylyltransferase (Thg1) superfamily includes enzymes that are found in all three domains of life that all share the common ability to catalyze the 3' to 5' synthesis of nucleic acids. This catalytic activity is the reverse of all other known DNA and RNA polymerases. Forward 5' to 3' and reverse 3' to 5' polymerization are mechanistically similar. In bacteria and many archaea, the G-1 residue is genomically encoded and transcribed in the precursor tRNA transcript, and subsequent cleavage of the 5' leader sequence by ribonuclease P (RNase P) yields a mature tRNAHis with its identity-establishing G-1 element (tRNAHisG-1). Different pathways to establish tRNAHis identity, overview |
761202 |
| 2.7.7.79 | evolution |
the tRNAHis guanylyltransferase (Thg1) superfamily includes enzymes that are found in all three domains of life that all share the common ability to catalyze the 3' to 5' synthesis of nucleic acids. This catalytic activity is the reverse of all other known DNA and RNA polymerases. Forward 5' to 3' and reverse 3' to 5' polymerization are mechanistically similar. In bacteria and many archaea, the G-1 residue is genomically encoded and transcribed in the precursor tRNA transcript, and subsequent cleavage of the 5' leader sequence by ribonuclease P (RNase P) yields a mature tRNAHis with its identity-establishing G-1 element (tRNAHisG-1). Different pathways to establish tRNAHis identity, overview. Thg1-like proteins function in tRNA repair, TLPs in bacteria and archaea, structural comparison of Thg1 and TLPs. TLPs exhibit broader RNA recognition properties than Thg1 homologues |
-, 761202 |
| 2.7.7.79 | evolution |
tRNAHis guanylyltransferase (Thg1) specifies eukaryotic tRNAHis identity by catalyzing a 3' to 5' non-Watson Crick (WC) addition of guanosine to the 5'-end of tRNAHis. Thg1 family enzymes in Archaea and Bacteria, called Thg1-like-proteins (TLPs), catalyze a similar but distinct 3' to 5' addition in an exclusively WC-dependent manner |
-, 761088 |
| 2.7.7.79 | evolution |
tRNAHis guanylyltransferase (Thg1) specifies eukaryotic tRNAHis identity by catalyzing a 3' to 5' non-Watson Crick (WC) addition of guanosine to the 5'-end of tRNAHis. Thg1 homologs known as Thg1-like proteins (TLPs) are found in all three domains of life and are biochemically distinct from Thg1. Thg1 family enzymes in Archaea and Bacteria, called Thg1-like-proteins (TLPs), catalyze a similar but distinct 3' to 5' addition in an exclusively WC-dependent manner, alternative non-tRNAHis-related functions for these enzymes , overview |
-, 761088 |
| 2.7.7.79 | evolution |
tRNAHis guanylyltransferase (Thg1) specifies eukaryotic tRNAHis identity by catalyzing a 3' to 5' non-Watson Crick (WC) addition of guanosine to the 5'-end of tRNAHis. Thg1 homologs known as Thg1-like proteins (TLPs) are found in all three domains of life and are biochemically distinct from Thg1. Thg1 family enzymes in Archaea and Bacteria, called Thg1-like-proteins (TLPs), catalyze a similar but distinct 3' to 5' addition in an exclusively WC-dependent manner, alternative non-tRNAHis-related functions for these enzymes, overview |
761088 |
