Architecture of the ubiquitylation module of the yeast Ccr4-Not complex.
The Ccr4-Not complex regulates eukaryotic gene expression at multiple levels, including mRNA turnover, translational repression, and transcription. We have studied the ubiquitylation module of the yeast Ccr4-Not complex and addressed how E3 ligase binds cognate E2 and how it is tethered to the complex. The 2.8-Å resolution crystal structure of the N-terminal RING domain of Not4 in complex with Ubc4 shows the detailed interactions of this E3-E2 complex. The 3.6-Å resolution crystal structure of the C-terminal domain of the yeast Not4 in complex with the C-terminal domain of Not1 reveals how a largely extended region at the C-terminus of Not4 wraps around a HEAT-repeat region of Not1. This C-terminal region of Not4 is only partly conserved in metazoans, rationalizing its weaker Not1-binding properties. The structural and biochemical data show how Not1 can incorporate both the ubiquitylation module and the Not2-Not3/5 module concomitantly in the Ccr4-Not complex.
Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, Am Klopferspitz 18, 82152 Munich, Germany.
Varun
V
Bhaskar
Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, Am Klopferspitz 18, 82152 Munich, Germany.
Jérôme
J
Basquin
Department of Structural Cell Biology, Max-Planck-Institute of Biochemistry, Am Klopferspitz 18, 82152 Munich, Germany. Electronic address: conti@biochem.mpg.de.
Elena
E
Conti
D000595:Amino Acid Sequence; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000378:metabolism; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D011485:Protein Binding; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D012097:Repressor Proteins / Q000737:chemistry / Q000378:metabolism; D012260:Ribonucleases / Q000737:chemistry* / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism; D044763:Ubiquitin-Conjugating Enzymes / Q000737:chemistry / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000737:chemistry / Q000378:metabolism; D054875:Ubiquitination
C089931:CDC36 protein, S cerevisiae; C079592:CDC39 protein, S cerevisiae; D018797:Cell Cycle Proteins; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C501306:Ubc4 protein, S cerevisiae; D044763:Ubiquitin-Conjugating Enzymes; C086923:MOT2 protein, S cerevisiae; D044767:Ubiquitin-Protein Ligases; C078657:CCR4 protein, S cerevisiae; D012260:Ribonucleases