Monomer/Oligomer Quasi-Racemic Protein Crystallography

• Published in: Journal of the American Chemical Society Vol. 138; no. 43; pp. 14497 - 14502
• Main Authors: Gao, Shuai, Pan, Man, Zheng, Yong, Huang, Yichao, Zheng, Qingyun, Sun, Demeng, Lu, Lining, Tan, Xiaodan, Tan, Xianglong, Lan, Huan, Wang, Jiaxing, Wang, Tian, Wang, Jiawei, Liu, Lei
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 02.11.2016
• Subjects: Amino Acid Sequence; crystal structure; crystallography; Crystallography, X-Ray; Models, Molecular; Protein Multimerization; Protein Structure, Quaternary; Stereoisomerism; Ubiquitin - chemistry; X-radiation
• ISSN: 0002-7863; 1520-5126; 1520-5126
• DOI: 10.1021/jacs.6b09545

Racemic or quasi-racemic crystallography recently emerges as a useful technology for solution of the crystal structures of biomacromolecules. It remains unclear to what extent the biomacromolecules of opposite handedness can differ from each other in racemic or quasi-racemic crystallography. Here we report a finding that monomeric d-ubiquitin (Ub) has propensity to cocrystallize with different dimers, trimers, and even a tetramer of l-Ub. In these cocrystals the unconnected monomeric d-Ubs can self-assemble to form pseudomirror images of different oligomers of l-Ub. This monomer/oligomer cocrystallization phenomenon expands the concept of racemic crystallography. Using the monomer/oligomer cocrystallization technology we obtained, for the first time the X-ray structures of linear M1-linked tri- and tetra-Ubs and a K11/K63-branched tri-Ub.