title: The N-end rule in bacteria.
abstract: The N-end rule relates the in vivo half-life of a protein to the identity of its amino-terminal residue. Distinct versions of the N-end rule operate in all eukaryotes examined. It is shown that the bacterium Escherichia coli also has the N-end rule pathway. Amino-terminal arginine, lysine, leucine, phenylalanine, tyrosine, and tryptophan confer 2-minute half-lives on a test protein; the other amino-terminal residues confer greater than 10-hour half-lives on the same protein. Amino-terminal arginine and lysine are secondary destabilizing residues in E. coli because their activity depends on their conjugation to the primary destabilizing residues leucine or phenylalanine by leucine, phenylalanine-transfer RNA-protein transferase. The adenosine triphosphate-dependent protease Clp (Ti) is required for the degradation of N-end rule substrates in E. coli.
authors.affiliation: Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
authors.forename: J W
authors.initials: JW
authors.lastname: Tobias
authors.forename: T E
authors.initials: TE
authors.lastname: Shrader
authors.forename: G
authors.initials: G
authors.lastname: Rocap
authors.forename: A
authors.initials: A
authors.lastname: Varshavsky
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001419:Bacteria / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000378:metabolism; D006207:Half-Life; D007700:Kinetics; D008969:Molecular Sequence Data; D011817:Rabbits; D012156:Reticulocytes / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000378:metabolism; D013329:Structure-Activity Relationship; D001616:beta-Galactosidase / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D001616:beta-Galactosidase