3CRQ

Structure of tRNA Dimethylallyltransferase: RNA Modification through a Channel

Summary for 3CRQ

• Entry DOI: 10.2210/pdb3crq/pdb
• Related: 3CRM 3CRR
• Descriptor: tRNA delta(2)-isopentenylpyrophosphate transferase, MAGNESIUM ION, DIPHOSPHATE, ... (4 entities in total)
• Functional Keywords: transferase, atp-binding, nucleotide-binding, nucleotidyltransferase, trna processing
• Biological source: Pseudomonas aeruginosa
• Total number of polymer chains: 1
• Total formula weight: 36042.36

Authors

Huang, R.H.,Xie, W.,Zhou, C. (deposition date: 2008-04-07, release date: 2008-04-29, Last modification date: 2024-02-21)

Primary citation

Xie, W.,Zhou, C.,Huang, R.H.
Structure of tRNA Dimethylallyltransferase: RNA Modification through a Channel
J.Mol.Biol., 367:872-881, 2007

PubMed Abstract: Dimethylallyltransferase (DMATase) transfers a five-carbon isoprenoid moiety from dimethylallyl pyrophosphate (DMAPP) to the amino group of adenosine at position 37 of certain tRNAs. Reported here are the crystal structures of Pseudomonas aeruginosa DMATase alone and in complex with pyrophosphate at 1.9 A resolution. Surprisingly, the enzyme possesses a central channel spanning the entire width of the enzyme. Both the accepting substrate tRNA and the donating substrate DMAPP appear to enter the channel from opposite sides in an ordered sequence, with tRNA first and DMAPP second, and the RNA modification reaction occurs in the middle of the channel once the two substrates have met. The structure of DMATase is homologous to a class of small soluble kinases involved in biosynthesis of nucleotide precursors for nucleic acids, indicating its possibly evolutionary origin. Furthermore, specific recognition of the pyrophosphate by a conserved loop in DMATase, similar to the P-loop commonly seen in diverse nucleotide-binding proteins, demonstrates that DMATase is structurally and mechanistically distinct from farnesyltransferase, another family of prenyltransferases involved in protein modification.

PubMed: 17292915
DOI: 10.1016/j.jmb.2007.01.048

Experimental method

X-RAY DIFFRACTION (2.2 Å)