HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Heller, H. Articles by Hershko, A. Search for Related Content PubMed PubMed Citation Articles by Heller, H. Articles by Hershko, A. Social Bookmarking                      What's this?

J. Biol. Chem., Vol. 265, Issue 12, 6532-6535, 04, 1990

A ubiquitin-protein ligase specific for type III protein substrates

H Heller and A Hershko
Unit of Biochemistry, Faculty of Medicine, Technion-Israel Institute of Technology, Haifa.

A previously studied species of ubiquitin-protein ligase contains specific sites for the binding of basic (Type I) and bulky hydrophobic (Type II) NH2-terminal amino acid residues of protein substrates. We now describe another enzyme that ligates ubiquitin specifically to proteins that have NH2-terminal residues other than the above two categories (Type III substrates). The new species of ligase, that we call E3 beta, is separable from the formerly described ligase (termed E3 alpha) by affinity chromatography on protein substrate columns. E3 beta was partially purified from extracts of rabbit reticulocytes and was shown to be required for the breakdown of Type III proteins. Apart from its different substrate specificity, it resembles E3 alpha in some physical properties, in a requirement for ubiquitin carrier protein (E2) for conjugate formation, and in its action to ligate multiple ubiquitin units to the substrate protein. The denatured derivative of bovine pancreatic ribonuclease is a specific substrate for E3 alpha, while that of ribonuclease S-protein is a good substrate for E3 beta. Since S-protein is formed by the removal from ribonuclease of NH2- terminal S-peptide, it is suggested that E3 beta interacts with an NH2- terminal determinant exposed in ribonuclease S-protein.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				T. Tasaki, L. C. F. Mulder, A. Iwamatsu, M. J. Lee, I. V. Davydov, A. Varshavsky, M. Muesing, and Y. T. Kwon A Family of Mammalian E3 Ubiquitin Ligases That Contain the UBR Box Motif and Recognize N-Degrons Mol. Cell. Biol., August 15, 2005; 25(16): 7120 - 7136. [Abstract] [Full Text] [PDF]

				Y. T. Kwon, Z. Xia, I. V. Davydov, S. H. Lecker, and A. Varshavsky Construction and Analysis of Mouse Strains Lacking the Ubiquitin Ligase UBR1 (E3alpha ) of the N-End Rule Pathway Mol. Cell. Biol., December 1, 2001; 21(23): 8007 - 8021. [Abstract] [Full Text] [PDF]

				O. V. Baboshina, R. Crinelli, T. J. Siepmann, and A. L. Haas N-end Rule Specificity within the Ubiquitin/Proteasome Pathway Is Not an Affinity Effect J. Biol. Chem., October 12, 2001; 276(42): 39428 - 39437. [Abstract] [Full Text] [PDF]

				S. Kumar, A. L. Talis, and P. M. Howley Identification of HHR23A as a Substrate for E6-associated Protein-mediated Ubiquitination J. Biol. Chem., June 25, 1999; 274(26): 18785 - 18792. [Abstract] [Full Text] [PDF]

				O. V. Baboshina and A. L. Haas Novel Multiubiquitin Chain Linkages Catalyzed by the Conjugating Enzymes E2[IMAGE] and RAD6 Are Recognized by 26 S Proteasome Subunit 5 J. Biol. Chem., February 2, 1996; 271(5): 2823 - 2831. [Abstract] [Full Text] [PDF]

				H. Gonen, I. Stancovski, D. Shkedy, T. Hadari, B. Bercovich, E. Bengal, S. Mesilati, O. Abu-Hatoum, A. L. Schwartz, and A. Ciechanover Isolation, Characterization, and Partial Purification of a Novel Ubiquitin-Protein Ligase, E3 J. Biol. Chem., January 5, 1996; 271(1): 302 - 310. [Abstract] [Full Text] [PDF]

				A. Varshavsky The N-end Rule Cold Spring Harb Symp Quant Biol, January 1, 1995; 60(0): 461 - 478. [Abstract] [PDF]

				J F Watkins, P Sung, S Prakash, and L Prakash The extremely conserved amino terminus of RAD6 ubiquitin-conjugating enzyme is essential for amino-end rule-dependent protein degradation. Genes & Dev., February 1, 1993; 7(2): 250 - 261. [Abstract] [PDF]