Structure of IDP90258
2.35 Angstrom resolution crystal structure of a putative tRNA (guanine-7-)-methyltransferase (trmD) from Staphylococcus aureus subsp. aureus MRSA252
- CSGID target
- IDP90258
- PDB Id
- 3KY7 (NCBI MMDB)
- Authors
- Halavaty, A.S., Minasov, G., Winsor, J., Dubrovska, I., Shuvalova, L., See, R., Zoraghi, R., Reiner, N., Anderson, W.F., Center for Structural Genomics of Infectious Diseases (CSGID)
- Responsible person
- Andrei Halavaty
- Responsible lab
- Northwestern University
- Deposition Date
- Dec 04, 2009
- Release Date
- Dec 22, 2009
Annotation
- Description
- Methyltransferases (methylases) use S-adenosylmethione (SAM) as a cofactor for tRNA methylation reactions. All five known classes of methyltransferases of the TrmD and SpoU families have a distinct alpha/beta topology and considered to be structurally different enzymes. In the structure of a putative tRNA (guanine-7-)-methyltransferase (trmD) from Staphylococcus aureus (Staph), two domains, N-terminal SAM-binding domain and C-terminal RNA-binding domain, of the protein are interconnected with a long partially unfolded loop region. The core of the N-terminal domain made up of six parallel beta-strands resembling structural fold of the class IV methylases of the SpoU family. Six strands are flanked by helices with the final three strands are folded into a rare deep trefoil knot, which provides the binding site for the cofactor. TrmD is believed to function as a dimer that is formed in parallel fashion by symmetry operation in the P4332 space group of the Staph protein. Such quaternary architecture localized two active sites in a close proximity to each other. The disordered inter-domain linker is a characteristic feature of the apo-methyltransferases. Based on literature data, the flexible loop between two domains appears to possibly cover the SAM-active site upon binding of the cognate tRNA and providing a candidate for the catalytic base. The C-terminal domain has a lower average B-factor than the catalytic domain and shows structural similarity to DNA-binding domains of trp and tet repressors. Co-crystallization of the Staph TrmD with its cofactor can help in understanding the mechanism and inhibition of the methylation reaction.
- Functional assignment
- Methyltransferase
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Ligands
| Ligand code | Name | Ligand type |
|---|---|---|
| OCS | cysteinesulfonic acid | crystallization |
Structure information
Unit cell parameters
- Space Group
- P 43 3 2
- Unit Cell
-
a=125.18Å, b=125.18Å, c=125.18Å
α=90.00, β=90.00, γ=90.00 - Solvent content
- 53.56
- Matthews coefficient
- 2.65
- Resolution range
- 27.32-2.35Å (2.41-2.35Å)
- Rall(%)
- 21.1
- Rwork(%)/dt>
- 20.9 (26.3)
- Rfree(%)
- 25.5 (32.3)
- Num. observed reflections
- 14517 (1055)
- Num. Rfree reflections
- 725 (57)
- Completeness(%)
- 99.8 (100.0)
- Num Atoms
- 1850
- Num Waters
- 83
- Num Hetatoms
- 95
- Model mean isotropic B factor (Å2)
- 24.520
- RMSD bond length (Å)
- 0.014
- RMSD bond angle
- 1.746°
- Filename uploaded
- 3KY7.pdb (uploaded on Sep 17, 2010 5:37 PM)
- Inserted
- Dec 09, 2009
