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Intersubunit linker length as a modifier of protein stability: Crystal structures and thermostability of mutant TRAP
Author(s) -
Watanabe Masahiro,
Mishima Yumiko,
Yamashita Ichiro,
Park SamYong,
Tame Jeremy R.H.,
Heddle Jonathan G.
Publication year - 2008
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1110/ps.073059308
Subject(s) - thermostability , linker , protein engineering , protein subunit , protein stability , chemistry , peptide , crystallography , modular design , trap (plumbing) , biophysics , nanotechnology , materials science , biology , biochemistry , physics , computer science , enzyme , gene , operating system , meteorology
The ability of proteins to self‐assemble into complex, functional nanoscale structures is expected to become of significant use in the manufacture of artificial nanodevices with a wide range of novel applications. The bacterial protein TRAP has potential uses as a nanoscale component as it is ring‐shaped, with a central, modifiable cavity. Furthermore, it can be engineered to make a ring of 12‐fold symmetry, which is advantageous for packing into two‐dimensional arrays. The 12mer form of TRAP is made by linking multiple subunits together on the same polypeptide, but the usefulness of the 12mers described to date is limited by their poor stability. Here we show that, by altering the length of the peptide linker between subunits, the thermostability can be significantly improved. Since the subunit interfaces of the different 12mers are essentially identical, stabilization arises from the reduction of strain in the linkers. Such a simple method of controlling the stability of modular proteins may have wide applications, and demonstrates the lack of absolute correlation between interactions observable by crystallography and the internal energy of a complex.