Microbial beta gamma -crystallins

beta gamma -Crystallins have emerged as a superfamily of structurally homologous proteins with representatives across the domains of life. A major portion of this superfamily is constituted by members from microorganisms. This superfamily has also been recognized as a novel group of Ca super(2+)-binding proteins with huge diversity. The beta gamma domain shows variable properties in Ca super(2+) binding, stability and association with other domains. The various members present a series of evolutionary adaptations culminating in great diversity in properties and functions. Most of the predicted beta gamma -crystallins are yet to be characterized experimentally. In this review, we outline the distinctive features of microbial beta gamma -crystallins and their position in the beta gamma -crystallin superfamily.