RRC ID 35478
Author Wang KT, Desmolaize B, Nan J, Zhang XW, Li LF, Douthwaite S, Su XD.
Title Structure of the bifunctional methyltransferase YcbY (RlmKL) that adds the m7G2069 and m2G2445 modifications in Escherichia coli 23S rRNA.
Journal Nucleic Acids Res.
Abstract The 23S rRNA nucleotide m(2)G2445 is highly conserved in bacteria, and in Escherichia coli this modification is added by the enzyme YcbY. With lengths of around 700 amino acids, YcbY orthologs are the largest rRNA methyltransferases identified in Gram-negative bacteria, and they appear to be fusions from two separate proteins found in Gram-positives. The crystal structures described here show that both the N- and C-terminal halves of E. coli YcbY have a methyltransferase active site and their folding patterns respectively resemble the Streptococcus mutans proteins Smu472 and Smu776. Mass spectrometric analyses of 23S rRNAs showed that the N-terminal region of YcbY and Smu472 are functionally equivalent and add the m(2)G2445 modification, while the C-terminal region of YcbY is responsible for the m(7)G2069 methylation on the opposite side of the same helix (H74). Smu776 does not target G2069, and this nucleotide remains unmodified in Gram-positive rRNAs. The E.coli YcbY enzyme is the first example of a methyltransferase catalyzing two mechanistically different types of RNA modification, and has been renamed as the Ribosomal large subunit methyltransferase, RlmKL. Our structural and functional data provide insights into how this bifunctional enzyme evolved.
Volume 40(11)
Pages 5138-48
Published 2012-6
DOI 10.1093/nar/gks160
PII gks160
PMID 22362734
PMC PMC3367195
MeSH Catalytic Domain Escherichia coli / enzymology Escherichia coli / genetics Escherichia coli Proteins / chemistry* Escherichia coli Proteins / metabolism Evolution, Molecular Methyltransferases / chemistry* Methyltransferases / metabolism Models, Molecular RNA, Ribosomal, 23S / chemistry RNA, Ribosomal, 23S / metabolism* Streptococcus mutans / enzymology
IF 11.147
Times Cited 6
Prokaryotes E. coli JW0931-KC ME9062(BW25113)?