The regions of securin and cyclin B proteins recognized by the ubiquitination machinery are natively unfolded

• Published in: FEBS letters Vol. 527; no. 1-3; pp. 303 - 308
• Main Authors: Cox, Cathleen J, Dutta, Kaushik, Petri, Edward T, Hwang, William C, Lin, Yaqiong, Pascal, Steven M, Basavappa, Ravi
• Format: Journal Article
• Language: English
• Published: England 11.09.2002
• Subjects: Amino Acid Sequence; APC/C, anaphase promoting complex/cyclosome; CD, circular dichroism; Cell Cycle Proteins; Circular Dichroism; Cyclin B; Cyclin B - chemistry; Cyclin B - metabolism; Fungal Proteins - chemistry; Fungal Proteins - metabolism; HeLa Cells; Humans; Magnetic Resonance Spectroscopy; Mitosis; Models, Molecular; Molecular Sequence Data; Natively unfolded; NMR, nuclear magnetic resonance; NOE, nuclear Overhauser effect; Nuclear magnetic resonance; Nuclear Proteins - chemistry; Nuclear Proteins - metabolism; Protein Folding; Saccharomyces cerevisiae Proteins; Securin; Sequence Homology, Amino Acid; Ubiquitin - metabolism
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/S0014-5793(02)03246-5

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.