Conserved Features in MsrB Sequences and Structures

<div><p>(A) Alignment of MsrB sequences corresponding to the active sites in these proteins. Catalytic Cys (C) and Sec (U) residues are shown in red. The conserved His, Val/Ile, and Asn residues in Cys-containing proteins are indicated in green, whereas the corresponding residues (Gly, Glu, and Phe, respectively) in selenoprotein MsrB1 are highlighted in yellow. Gray shows other conserved residues. Numbering of amino acids is shown above the sequences and is based on the mouse MsrB1 sequence.</p> <p>(B) Structure of the active site of <i>N. gonorrhoeae</i> MsrB domain (1L1D). For convenience, some active-site residues are not shown. Numbering of amino acids is based on the mouse MsrB1 sequence. The Cys41 is the resolving Cys. It is absent in all mammalian MsrBs.</p> <p>(C) Alignment of mouse and human MsrB sequences. Catalytic Cys (C) and Sec (U) residues are shown in red. Pink indicates Ser and Thr residues that replace the conserved resolving Cys residues in many MsrB proteins. Zinc-coordinating Cys residues are shown in yellow. Other conserved Cys residues in each mouse and human MsrB sequence are indicated in green, whereas non-conserved Cys residues are shown in gray. Residues corresponding to Cys4 in MsrB1 are highlighted in turquoise.</p>