title: A novel 3-methylhistidine modification of yeast ribosomal protein Rpl3 is dependent upon the YIL110W methyltransferase.
abstract: We have shown that Rpl3, a protein of the large ribosomal subunit from baker's yeast (Saccharomyces cerevisiae), is stoichiometrically monomethylated at position 243, producing a 3-methylhistidine residue. This conclusion is supported by top-down and bottom-up mass spectrometry of Rpl3, as well as by biochemical analysis of Rpl3 radiolabeled in vivo with S-adenosyl-l-[methyl-(3)H]methionine. The results show that a +14-Da modification occurs within the GTKKLPRKTHRGLRKVAC sequence of Rpl3. Using high-resolution cation-exchange chromatography and thin layer chromatography, we demonstrate that neither lysine nor arginine residues are methylated and that a 3-methylhistidine residue is present. Analysis of 37 deletion strains of known and putative methyltransferases revealed that only the deletion of the YIL110W gene, encoding a seven β-strand methyltransferase, results in the loss of the +14-Da modification of Rpl3. We suggest that YIL110W encodes a protein histidine methyltransferase responsible for the modification of Rpl3 and potentially other yeast proteins, and now designate it Hpm1 (Histidine protein methyltransferase 1). Deletion of the YIL110W/HPM1 gene results in numerous phenotypes including some that may result from abnormal interactions between Rpl3 and the 25 S ribosomal RNA. This is the first report of a methylated histidine residue in yeast cells, and the first example of a gene required for protein histidine methylation in nature.
authors.affiliation: Department of Chemistry and Biochemistry and the Molecular Biology Institute, University of California Los Angeles, Los Angeles, California 90095-1569, USA.
authors.forename: Kristofor J
authors.initials: KJ
authors.lastname: Webb
authors.forename: Cecilia I
authors.initials: CI
authors.lastname: Zurita-Lopez
authors.forename: Qais
authors.initials: Q
authors.lastname: Al-Hadid
authors.forename: Arthur
authors.initials: A
authors.lastname: Laganowsky
authors.forename: Brian D
authors.initials: BD
authors.lastname: Young
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Lipson
authors.forename: Puneet
authors.initials: P
authors.lastname: Souda
authors.forename: Kym F
authors.initials: KF
authors.lastname: Faull
authors.forename: Julian P
authors.initials: JP
authors.lastname: Whitelegge
authors.forename: Steven G
authors.initials: SG
authors.lastname: Clarke
mesh_terms: D000595:Amino Acid Sequence; D008762:Methylhistidines / Q000378:metabolism*; D008780:Methyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment
chemical_list: D008762:Methylhistidines; D012269:Ribosomal Proteins; C521718:Rpl3 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C000609573:Hpm1 protein, S cerevisiae; D008780:Methyltransferases; C028118:3-methylhistidine