Structural and Functional Studies of the Thermus Thermophilus 16S rRNA Methyltransferase RsmG
The RsmG methyltransferase is responsible for N7 methylation of G527 of 16S rRNA in bacteria. Here, we report the identification of the Thermus thermophilus rsmG gene, the isolation of rsmG mutants, and the solution of RsmG X-ray crystal structures at up to 1.5 A resolution. Like their counterparts in other species, T. thermophilus rsmG mutants are weakly resistant to the aminoglycoside antibiotic streptomycin. Growth competition experiments indicate a physiological cost to loss of RsmG activity, consistent with the conservation of the modification site in the decoding region of the ribosome. In contrast to Escherichia coli RsmG, which has been reported to recognize only intact 30S subunits, T. thermophilus RsmG shows no in vitro methylation activity against native 30S subunits, only low activity with 30S subunits at low magnesium concentration, and maximum activity with deproteinized 16S rRNA. Cofactor-bound crystal structures of RsmG reveal a positively charged surface area remote from the active site that binds an adenosine monophosphate molecule. We conclude that an early assembly intermediate is the most likely candidate for the biological substrate of RsmG.
- Research Organization:
- Brookhaven National Laboratory (BNL) National Synchrotron Light Source
- Sponsoring Organization:
- Doe - Office Of Science
- DOE Contract Number:
- AC02-98CH10886
- OSTI ID:
- 980495
- Report Number(s):
- BNL--93413-2010-JA
- Journal Information:
- RNA, Journal Name: RNA Vol. 15
- Country of Publication:
- United States
- Language:
- English
Similar Records
Multi-site-specific 16S rRNA Methyltransferase RsmF from Thermus thermophilus
Structural Rearrangements in the Active Site of the Thermus thermophilus 16S rRNA Methyltransferase KsgA in a Binary Complex with 5'-Methylthioadenosine
Crystal Structure of the Thermus thermophilus 16 S rRNA Methyltransferase RsmC in Complex with Cofactor and Substrate Guanosine
Journal Article
·
Thu Dec 31 23:00:00 EST 2009
· RNA
·
OSTI ID:1019993
Structural Rearrangements in the Active Site of the Thermus thermophilus 16S rRNA Methyltransferase KsgA in a Binary Complex with 5'-Methylthioadenosine
Journal Article
·
Wed Dec 31 23:00:00 EST 2008
· Journal of Molecular Biology
·
OSTI ID:980530
Crystal Structure of the Thermus thermophilus 16 S rRNA Methyltransferase RsmC in Complex with Cofactor and Substrate Guanosine
Journal Article
·
Mon Dec 31 23:00:00 EST 2007
· Journal of Biological Chemistry
·
OSTI ID:980110