Library of 18 β turns and their Assignment Tool for mmCIF and PDB structure files

The software tool, BetaTurn18 reads a protein structure in mmCIF or PDB format, locates beta turns and assigns their types using our 2018 library, BetaTurnLib18 with 18 beta-turn types. BetaTurnLib18 includes conformational centroids and medoids of 18 beta-turn types. It is provided in 3 formats: a plain-text tab-delimited file, PDF and XLSX spreadsheet.

License and Availability

Both the beta-turn tool and library can be downloaded for further use in third-party tools and software. The tool and library are free, open-source, redistributable and modifiable under BSD 3-Clause License. We adopted the software for 3 operating systems: Unix, Mac and Windows. It automatically downloads required Python tools. The only requirement is to have python2 installed.


The software and usage instructions for BetaTurn18 and BetaTurnLib18 are available from


A new clustering and nomenclature for beta turns derived from high-resolution protein structures.
Maxim Shapovalov, Slobodan Vucetic, Roland L. Dunbrack Jr, PLoS Comput Biol 2019, 15(3): e1006844. Article