RepeatParam: Algorithm for Parameterising Repeat Proteins and Analysis of Repeat Protein Architectures

Motivation: Tandem repeat proteins consist of repetitive sequence and structure motifs and have diverse roles in Nature for molecular recognition and signalling. The architecture of repeat proteins can be described using simple helical parameters. Understanding these structural features can inform both the function of these proteins and be used to parametrically design new proteins. Despite their importance, no existing program is capable of completely parameterising repeat proteins. Results: Here we describe a novel repeat protein parameterisation algorithm, RepeatParam, and a comprehensive repeat protein dataset. RepeatParam determines a helix that defines the global protein architecture and a superhelix that describes the relationship between consecutive repeats. We analyse the relationships between helical parameters and families of different repeat proteins.