title: Recognition of G-1:C73 atomic groups by Escherichia coli histidyl-tRNA synthetase.
abstract: This work focuses on the RNA-protein interactions necessary for efficient aminoacylation of tRNAHis by Escherichia coli histidyl-tRNA synthetase (HisRS). The E. coli tRNAHis acceptor stem is characterized by a unique "extra" G-1:C73 base pair. Previous in vivo and in vitro studies showed that G-1:C73 is a major recognition element for E. coli HisRS. To further probe the role of the G-1:C73 base pair in specific aminoacylation, we carried out atomic group "mutagenesis" studies. Systematic base analogue substitutions at the -1:73 position of chemically synthesized microhelixHis substrates suggest that the G-1 base serves to position the 5'-monophosphate, which is critical for aminoacylation. Additionally, the C73 and G-1 bases contain major groove exocyclic atomic groups that contribute to HisRS recognition.
authors.affiliation: Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA. musier@chem.umn.edu
authors.forename: Abbey E
authors.initials: AE
authors.lastname: Rosen
authors.forename: Karin
authors.initials: K
authors.lastname: Musier-Forsyth
mesh_terms: D020029:Base Pairing; D004926:Escherichia coli / Q000201:enzymology*; D006643:Histidine-tRNA Ligase / Q000737:chemistry* / Q000378:metabolism*; D009690:Nucleic Acid Conformation; D012346:RNA, Transfer, Amino Acyl / Q000737:chemistry* / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D012346:RNA, Transfer, Amino Acyl; D006643:Histidine-tRNA Ligase