Tandem sequence repeats in transmembrane channel proteins

Abstract

The flow of ions and small molecules out of and between cells is mediated by various classes of transmembrane proteins. One group of putative channel proteins, including the abundant lens protein MIP, is widely distributed from prokaryotes to vertebrates. This article suggests that these proteins contain a structural twofold repeat and may have arisen by gene duplication. Such a model has implications for the tertiary structures of these important proteins.