1UAL: Crystal Structure Of Trna(M1g37)methyltransferase: Insight Into Trna Recognition

tRNA(m(1)G37)methyltransferase (TrmD) catalyzes the transfer of a methyl group from S-adenosyl-L- methionine (AdoMet) to G(37) within a subset of bacterial tRNA species, which have a G residue at the 36th position. The modified guanosine is adjacent to and 3' of the anticodon and is essential for the maintenance of the correct reading frame during translation. Here we report four crystal structures of TrmD from Haemophilus influenzae, as binary complexes with either AdoMet or S-adenosyl-L-homocysteine (AdoHcy), as a ternary complex with AdoHcy and phosphate, and as an apo form. This first structure of TrmD indicates that it functions as a dimer. It also suggests the binding mode of G(36)G(37) in the active site of TrmD and the catalytic mechanism. The N-terminal domain has a trefoil knot, in which AdoMet or AdoHcy is bound in a novel, bent conformation. The C-terminal domain shows structural similarity to trp repressor. We propose a plausible model for the TrmD(2)-tRNA(2) complex, which provides insights into recognition of the general tRNA structure by TrmD.
PDB ID: 1UALDownload
MMDB ID: 23677
PDB Deposition Date: 2003/3/11
Updated in MMDB: 2012/10
Experimental Method:
x-ray diffraction
Resolution: 1.8  Å
Source Organism:
Similar Structures:
Biological Unit for 1UAL: dimeric; determined by author and by software (PISA,PQS)
Molecular Components in 1UAL
Label Count Molecule
Proteins (2 molecules)
tRNA (Guanine-n(1)-)-methyltransferase(Gene symbol: trmD)
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB