Back to Search
Start Over
Structures of a putative RNA 5-methyluridine methyltransferase, thermus thermophilus TTHA1280, and its complex with S-adenosyl-L-homocysteine.
- Source :
- Acta Crystallographica: Section F (Wiley-Blackwell); Oct2005, Vol. 61 Issue 10, p867-874, 8p
- Publication Year :
- 2005
-
Abstract
- The Thermus thermophilus hypothetical protein TTHA1280 belongs to a family of predicted S-adenosyl-l-methionine (AdoMet) dependent RNA methyltransferases (MTases) present in many bacterial and archaeal species. Inspection of amino-acid sequence motifs common to class I Rossmann-fold-like MTases suggested a specific role as an RNA 5-methyluridine MTase. Selenomethionine (SeMet) labelled and native versions of the protein were expressed, purified and crystallized. Two crystal forms of the SeMet-labelled apoprotein were obtained: SeMet-ApoI and SeMet-ApoII. Cocrystallization of the native protein with S-adenosyl-L-homocysteine (AdoHcy) yielded a third crystal form, Native-AdoHcy. The SeMet-ApoI structure was solved by the multiple anomalous dispersion method and refined at 2.55 Å resolution. The SeMet-ApoII and Native-AdoHcy structures were solved by molecular replacement and refined at 1.80 and 2.60 Å , respectively. TTHA1280 formed a homodimer in the crystals and in solution. Each subunit folds into a three-domain structure composed of a small N-terminal PUA domain, a central α/β-domain and a C-terminal Rossmann-fold-like MTase domain. The three domains form an overall clamp-like shape, with the putative active site facing a deep cleft. The architecture of the active site is consistent with specific recognition of uridine and catalysis of methyl transfer to the 5-carbon position. The cleft is suitable in size and charge distribution for binding single-stranded RNA. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 17443091
- Volume :
- 61
- Issue :
- 10
- Database :
- Complementary Index
- Journal :
- Acta Crystallographica: Section F (Wiley-Blackwell)
- Publication Type :
- Academic Journal
- Accession number :
- 18503127
- Full Text :
- https://doi.org/10.1107/S1744309105029842