Structural and functional characterization of CFE88: Evidence that a conserved and essential bacterial protein is a methyltransferase
2009
CFE88 is a conserved
essential geneproduct from Streptococcus pneumoniae. This 227-residue protein has minimal sequence similarity to proteins of known 3Dstructure. Sequence alignment models and computational protein threading studies suggest that CFE88 is a
methyltransferase. Characterization of the conformation and function of CFE88 has been performed by using several techniques. Backbone atom and limited side-chain atom NMR resonance assignments have been obtained. The data indicate that CFE88 has two domains: an N-terminal domain with 163 residues and a C-terminal domain with 64 residues. The C-terminal domain is primarily helical, while the N-terminal domain has a mixed helical/extended (
Rossmann)
fold. By aligning the experimentally observed elements of secondary structure, an initial unrefined model of CFE88 has been constructed based on the X-ray structure of ErmC′
methyltransferase(
Protein Data Bankentry 1QAN). NMR and biophysical studies demonstrate binding of
S-adenosyl-L-homocysteine(SAH) to CFE88; these interactions have been localized by NMR to the predicted active site in the N-terminal domain. Mutants that target this predicted active site (H26W, E46R, and E46W) have been constructed and characterized. Overall, our results both indicate that CFE88 is a
methyltransferaseand further suggest that the
methyltransferaseactivity is essential for bacterial survival.
Keywords:
-
Correction
-
Source
-
Cite
-
Save
55
References
4
Citations
NaN
KQI