Superposition of vCCI and A41 structures with modelled SECRET and alignment of their sequences. (A) Superposition of vCCI, A41 and SECRET was made with CEalign . SECRET is red coloured, vCCI is shown in blue and A41 is green. Left panel shows surfaces formed by β-sheets I of these proteins. Right panel shows the same superposition rotated around y-axis by 90°. Characteristic long extended loop of vCCI is absent in A41 as well as in the SECRET. (B) Alignment of vCCI, A41 and SECRET amino acid sequences produced with structural alignment server TM-align . Alignment was manually edited taking in mind their secondary structures (shown above corresponding sequences) using Aline software . Numbering of amino acid residues in SECRET corresponds to that of full length VARV-CrmB protein (P34015). Gaps are shown as dots, sequences are coloured by amino acid similarity. Amino acid residues of vCCI and A41 are numbered according to numeration found in 1CQ3 and 2VGA PDB files, respectively.