3OTC

Crystal structure of human tRNAHis guanylyltransferase (Thg1)- Native II

Summary for 3OTC

• Entry DOI: 10.2210/pdb3otc/pdb
• Related: 3OTB 3OTC 3OTD 3OTE
• Descriptor: tRNA(His) guanylyltransferase (1 entity in total)
• Functional Keywords: guanylyltransferase, polymerase-like palm domain, catalytic carboxylates, transferase
• Biological source: Homo sapiens (human)
• Cellular location: Cytoplasm: Q9NWX6
• Total number of polymer chains: 2
• Total formula weight: 63257.88

Authors

Hyde, S.J.,Eckenroth, B.E.,Doublie, S. (deposition date: 2010-09-11, release date: 2010-11-17, Last modification date: 2024-02-21)

Primary citation

Hyde, S.J.,Eckenroth, B.E.,Smith, B.A.,Eberley, W.A.,Heintz, N.H.,Jackman, J.E.,Doublie, S.
tRNAHis guanylyltransferase (THG1), a unique 3'-5' nucleotidyl transferase, shares unexpected structural homology with canonical 5'-3' DNA polymerases.
Proc.Natl.Acad.Sci.USA, 107:20305-20310, 2010

PubMed Abstract: All known DNA and RNA polymerases catalyze the formation of phosphodiester bonds in a 5' to 3' direction, suggesting this property is a fundamental feature of maintaining and dispersing genetic information. The tRNA(His) guanylyltransferase (Thg1) is a member of a unique enzyme family whose members catalyze an unprecedented reaction in biology: 3'-5' addition of nucleotides to nucleic acid substrates. The 2.3-Å crystal structure of human THG1 (hTHG1) reported here shows that, despite the lack of sequence similarity, hTHG1 shares unexpected structural homology with canonical 5'-3' DNA polymerases and adenylyl/guanylyl cyclases, two enzyme families known to use a two-metal-ion mechanism for catalysis. The ability of the same structural architecture to catalyze both 5'-3' and 3'-5' reactions raises important questions concerning selection of the 5'-3' mechanism during the evolution of nucleotide polymerases.

PubMed: 21059936
DOI: 10.1073/pnas.1010436107

Experimental method

X-RAY DIFFRACTION (3.01 Å)