title: A new side to ubiquitin.
abstract: Mono-ubiquitination is a common mechanism of protein regulation, and more than ten ubiquitin-interacting domains that recognize the hydrophobic region centered on Ile44 of ubiquitin have been characterized. Two recent reports describe the crystal structure of the Rab5 guanine-nucleotide-exchange factor Rabex-5 and show that it contains two novel ubiquitin-binding domains. One of these is an A20 zinc finger that binds to a polar interaction interface of ubiquitin centered on Asp58. The discovery of an alternative interaction face of ubiquitin opens new avenues for understanding how this small protein regulates protein function.
authors.affiliation: Department of Biochemistry, the Norwegian Radium Hospital and the University of Oslo, Montebello, N-0310 Oslo, Norway.
authors.forename: Camilla
authors.initials: C
authors.lastname: Raiborg
authors.forename: Thomas
authors.initials: T
authors.lastname: Slagsvold
authors.forename: Harald
authors.initials: H
authors.lastname: Stenmark
mesh_terms: D000818:Animals; D020662:Guanine Nucleotide Exchange Factors / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008954:Models, Biological; D008958:Models, Molecular; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D025801:Ubiquitin / Q000737:chemistry / Q000378:metabolism*
chemical_list: D020662:Guanine Nucleotide Exchange Factors; C108382:RABGEF1 protein, human; D025801:Ubiquitin