title: A highly conserved 3-methylhistidine modification is absent in yeast actin.
abstract: To identify a protein histidine methyltransferase from Saccharomyces cerevisiae, we examined purified actin for the presence of the highly conserved 3-methylhistidine residue at position 73 by amino acid analysis of the whole protein and by amino acid analysis and mass spectrometry of the corresponding tryptic fragment. Surprisingly, we found that His-73 is not modified. A similar lack of modification was also found in actin from the yeast Candida albicans, while rabbit muscle actin revealed the expected 3-methylhistidine residue. Phylogenetic analysis of actin sequences suggests that this modification was introduced in evolution after the divergence of yeast from higher eukaryotic organisms, including unicellular eukaryotes such as Acanthamoeba, Dictyostelium, and Physarum, whose actins contain 3-methylhistidine. Our methodology for the analytical determination of 3-methylhistidine in actin offers an improved approach for investigating histidine methylation in proteins.
authors.affiliation: Department of Chemistry, University of California, Los Angeles, California, 90095, USA.
authors.forename: H R
authors.initials: HR
authors.lastname: Kalhor
authors.forename: A
authors.initials: A
authors.lastname: Niewmierzycka
authors.forename: K F
authors.initials: KF
authors.lastname: Faull
authors.forename: X
authors.initials: X
authors.lastname: Yao
authors.forename: S
authors.initials: S
authors.lastname: Grade
authors.forename: S
authors.initials: S
authors.lastname: Clarke
authors.forename: P A
authors.initials: PA
authors.lastname: Rubenstein
mesh_terms: D000199:Actins / Q000737:chemistry* / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D002176:Candida albicans / Q000378:metabolism; D017124:Conserved Sequence; D019143:Evolution, Molecular; D008762:Methylhistidines / Q000032:analysis / Q000378:metabolism*; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry; D010802:Phylogeny; D011496:Protein Methyltransferases / Q000378:metabolism*; D011817:Rabbits; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D018629:Spectrometry, Mass, Secondary Ion
chemical_list: D000199:Actins; D008762:Methylhistidines; D010446:Peptide Fragments; D011496:Protein Methyltransferases; C051284:protein-histidine methyltransferase; C028118:3-methylhistidine