title: UBA 1: an essential yeast gene encoding ubiquitin-activating enzyme.
abstract: All known functions of ubiquitin are mediated through its covalent attachment to other proteins. The post-translational formation of ubiquitin--protein conjugates is preceded by an ATP-requiring step in which the carboxyl terminus of ubiquitin is adenylated and subsequently joined, through a thiolester bond, to a cysteine residue in the ubiquitin-activating enzyme, also known as E1. We report the isolation and functional analysis of the gene (UBA1) for the ubiquitin-activating enzyme of the yeast Saccharomyces cerevisiae. UBA1 encodes a 114 kd protein whose amino acid sequence contains motifs characteristic of nucleotide-binding sites. Expression of catalytically active UBA1 protein in E. coli, which lacks the ubiquitin system, confirmed that the yeast UBA1 gene encodes a ubiquitin-activating enzyme. Deletion of the UBA1 gene is lethal, demonstrating that the formation of ubiquitin--protein conjugates is essential for cell viability.
authors.affiliation: Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
authors.forename: J P
authors.initials: JP
authors.lastname: McGrath
authors.forename: S
authors.initials: S
authors.lastname: Jentsch
authors.forename: A
authors.initials: A
authors.lastname: Varshavsky
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005800:Genes, Fungal; D006801:Humans; D008025:Ligases / Q000235:genetics*; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics* / Q000502:physiology; D012689:Sequence Homology, Nucleic Acid; D013172:Spores, Fungal / Q000502:physiology; D014158:Transcription, Genetic; D044764:Ubiquitin-Activating Enzymes; D044767:Ubiquitin-Protein Ligases
chemical_list: D015345:Oligonucleotide Probes; D044767:Ubiquitin-Protein Ligases; D008025:Ligases; D044764:Ubiquitin-Activating Enzymes