The regions of securin and cyclin B proteins recognized by the ubiquitination machinery are natively unfolded.
The proteins securin and cyclin B are destroyed in mitosis by the ubiquitin/proteasome system. This destruction is important to mitotic progression. The N-terminal regions of these proteins contain the sequence features recognized by the ubiquitination system. We have demonstrated using circular dichroism and 1-D and 2-D nuclear magnetic resonance that these rather substantial regions are natively unfolded. Based on these findings, we propose a model that helps to explain previously enigmatic observations.
Cox
Cathleen J
CJ
Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave., Rochester, NY 14618, USA.
Dutta
Kaushik
K
Petri
Edward T
ET
Hwang
William C
WC
Lin
Yaqiong
Y
Pascal
Steven M
SM
Basavappa
Ravi
R
D000595:Amino Acid Sequence; D018797:Cell Cycle Proteins; D002942:Circular Dichroism; D019926:Cyclin B / Q000737:chemistry* / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry* / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry* / Q000378:metabolism*; D017510:Protein Folding; D029701:Saccharomyces cerevisiae Proteins; D064249:Securin; D017386:Sequence Homology, Amino Acid; D025801:Ubiquitin / Q000378:metabolism
D018797:Cell Cycle Proteins; D019926:Cyclin B; D005656:Fungal Proteins; D009687:Nuclear Proteins; C578004:PDS1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D064249:Securin; D025801:Ubiquitin