Protein secondary structure class assignment on the basis of a new graphic representation

A novel 2D representation (M‐curve) has been provided to visualize the structure information of protein secondary structure sequences: (1) end point of the curve reflects difference of amino acid residue numbers in α‐helices and β‐strands of a protein; (2) Up/down ladder‐like structures in the curve show that α‐helices/β‐strands appear sequentially in this region; (3) triangular‐like/trapeziform‐like structures of the curve show that α‐helices and β‐strands appear alternatively in this region. So from the M‐curve, a protein could be directly assigned into corresponding secondary structure class. Moreover, a new numerical descriptor, four‐component vector, is introduced and applied to cluster analysis. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009