Evolution of Structural and Coordination Features Within the Methionine Sulfoxide Reductase B Family

In this review, we summarize the evolution, sequence, structural and coordination peculiarities of proteins belonging to the Methionine Sulfoxide Reductase B family (MsrBs). These proteins represent important redox proteins. MsrBs are found in all kingdoms of life. Whereas prokaryotes have only one type of MsrB, mammals possess three, MsrB1, MsrB2 and MsrB3, distributed in different cellular compartments, and regulated by alternative splicing and specific targeting signals. Structural analysis of mammalian and bacterial MsrBs revealed a well-conserved β-core, and dramatic variability in C-and N-terminus. Mostly, MsrBs contain structural zinc ions coordinated by four cysteines. However, some of MsrBs lack coordinating cysteines and, therefore may not contain zinc ion.