Application of helix fusion method in structural biology

다국어 초록 (Multilingual Abstract)

Generating artificial protein assemblies with complex shapes requires a method of connecting protein components withstable and predictable structures. Because they have uniform structures, alpha helices can provide an excellent linker forconnecting proteins with predictable structures. However, except for a few exceptional cases, early attempts to ligate twoproteins by fusion of terminal alpha helices were not successful. In order to solve this problem, several new methods havebeen developed in recent years. In the chemical cross-linker method, the linker helix is stabilized by a chemical cross-linkerthat can force an alpha helical geometry by fixing the distance between two cysteine residues. In the shared-helix method,the linker helix is generated by overlapping pairs of alpha helices by 1~2 turns using a molecular modeling program. Theamino acid sequence at the overlapped site is chosen from the two natural sequences that would stabilize the alphahelical linker. These two helix fusion methods are expected to be useful in structural biology because they can enhancethe crystallization property of challenging target proteins by providing a rigid and crystallizable surface. They also can beused to produce artificial protein complexes by connecting the target protein to a large backbone protein. The resultingprotein complex effectively increases the size of the target protein for cryo-electron microscopy study. In this review, wesummarize recent progress of the helix fusion methods and their application to structural study of challenging proteins.

참고문헌 (Reference)

1 Lai, Y.T., "Structure of a designed protein cage that self-assembles into a highly porous cube" 6 : 1065-1071, 2014

2 Lai, Y.T., "Structure of a 16-nm cage designed by using protein oligomers" 336 : 1129-, 2012

3 Iwata, S., "Structure at 28 A resolution of cytochrome c oxidase from Paracoccus denitrificans" 376 : 660-669, 1995

4 Hunte, C., "Structure at 2.3 A resolution of the cytochrome bc(1) complex from the yeast Saccharomyces cerevisiae co-crystallized with an antibody Fv fragment" 8 : 669-684, 2000

5 Yang, H.T., "Structural insight into the mechanisms of enveloped virus tethering by tetherin" 107 : 18428-18432, 2010

6 Liu, W., "Structural basis for allosteric regulation of GPCRs by sodium ions" 337 : 232-236, 2012

7 Zhang, F., "Stabilization of folded peptide and protein structures via distance matching with a long, rigid cross-linker" 129 : 14154-14155, 2007

8 Heinig, M., "STRIDE: a web server for secondary structure assignment from known atomic coordinates of proteins" 32 : W500-W502, 2004

9 Bukowska, M.A., "New concepts and aids to facilitate crystallization" 23 : 409-416, 2013

10 Liu, Y., "Near-atomic cryo-EM imaging of a small protein displayed on a designed scaffolding system" 2018

11 Padilla, J.E., "Nanohedra: using symmetry to design self assembling protein cages, layers, crystals, and filaments" 98 : 2217-2221, 2001

12 Ke, A., "Insights into binding cooperativity of MATa1/MATalpha2 from the crystal structure of a MATa1 homeodomainmaltose binding protein chimera" 12 : 306-312, 2003

13 Cherezov, V., "High-resolution crystal structure of an engineered human beta2-adrenergic G protein-coupled receptor" 318 : 1258-1265, 2007

14 Dutzler, R., "Gating the selectivity filter in ClC chloride channels" 300 : 108-112, 2003

15 Rosenbaum, D.M., "GPCR engineering yields high-resolution structural insights into beta2-adrenergic receptor function" 318 : 1266-1273, 2007

16 Chun, E., "Fusion partner toolchest for the stabilization and crystallization of G protein-coupled receptors" 20 : 967-976, 2012

17 Jin, T., "Design of an expression system to enhance MBP-mediated crystallization" 7 : 40991-, 2017

18 Batyuk, A., "DARPin-Based Crystallization Chaperones Exploit Molecular Geometry as a Screening Dimension in Protein Crystallography" 428 : 1574-1588, 2016

19 Youn, S.J., "Construction of novel repeat proteins with rigid and predictable structures using a shared helix method" 7 : 2595-, 2017

20 Jeong, W.H., "Connecting two proteins using a fusion alpha helix stabilized by a chemical cross linker" 7 : 11031-, 2016