Proteins are the functional basis of all biological processes and being able to control and improve their functions through design and engineering is one of the fundamental goals of synthetic biology. Protein splicing, a process in which a catalytically active internal polypeptide termed INTEIN excises itself from a precursor protein, has been used by our team to alter the functionalities of proteins in various ways post-translationally. We have developed a comprehensive toolbox compromising five sets of standardized parts that provide standard mechanisms for specific modifications of proteins:

1. A purification standard to faciliate purification of recombinant proteins. 2. A construct that allows for post-translational fusion of protein domains to produce synthetic proteins 3. A standard that allows for switching proteins ON and OFF. 4. One to oligomerize protein monomers. And 5. perhaps the most intriguing standard construct of this toolbox that was built to produce heat stable proteins, which can be achieved by circularization.

In order to offer a comfortable way to apply any of the above mechanisms to a protein and a biological system we designed a toolbox guide that provides step by step instructions for cloning based on the intein standard parts described in our RFC.