Substrate requirements for ErmC' methyltransferase activity.
AUTOR(ES)
Zhong, P
RESUMO
ErmC' is a methyltransferase that confers resistance to the macrolide-lincosamide-streptogramin B group of antibiotics by catalyzing the methylation of 23S rRNA at a specific adenine residue (A-2085 in Bacillus subtilis; A-2058 in Escherichia coli). The gene for ErmC' was cloned and expressed to a high level in E. coli, and the protein was purified to virtual homogeneity. Studies of substrate requirements of ErmC' have shown that a 262-nucleotide RNA fragment within domain V of B. subtilis 23S rRNA can be utilized efficiently as a substrate for methylation at A-2085. Kinetic studies of the monomethylation reaction showed that the apparent Km of this 262-nucleotide RNA oligonucleotide was 26-fold greater than the value determined for full-size and domain V 23S rRNA. In addition, the Vmax for this fragment also rose sevenfold. A model of RNA-ErmC' interaction involving multiple binding sites is proposed from the kinetic data presented.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=177180Documentos Relacionados
- Site and substrate specificity of the ermC 23S rRNA methyltransferase.
- Translational autoregulation of ermC 23S rRNA methyltransferase expression in Bacillus subtilis.
- Alanine-scanning mutagenesis of the predicted rRNA-binding domain of ErmC′ redefines the substrate-binding site and suggests a model for protein–RNA interactions
- Induction of ermC requires translation of the leader peptide.
- Identification of cis-acting sequences required for translational autoregulation of the ermC methylase.