Adaptations of proteins to cellular and subcellular pH

Abstract

Bioinformatics-based searches for correlations between subcellular localization and pI or charge distribution of proteins have failed to detect meaningful correlations. Recent work published in BMC Biology finds that a physicochemical metric of charge distribution correlates better with subcellular pH than does pI. See research article http://www.biomedcentral.com/1741-7007/7/69.

Figure 1

The distribution of ionizable residues (for example, the side chains of Arg, Lys, His, Asp and Glu) in proteins might reflect adaptations to cellular and intracellular pH. The search for these structural adaptations should consider the important roles of charged residues on the many different functional, structural, physical and biological factors that influenced the evolution of proteins, as indicated here.