Figure 1.

Sequence and structural analysis of the KilA-N domain. (a) Multiple alignment of KilA-N and APSES domains. Sequences are designated by their gene name, followed by species abbreviation and the Genbank index (gi) number. Species abbreviations are listed in Materials and methods. The coloring reflects the conservation profile at 80% consensus of amino acids. h, hydrophobic residues (L,I,Y,F,M,W,A,C,V in the single-letter amino-acid code); a,aromatic residues (F,H,Y,W); and l, aliphatic residues (L,I,A,V), all shaded yellow. c, charged residues (K,E,R,D,H); +, basic residues (K,R,H); -, acidic residues (D,E); and p, polar residues (S,T,E,D,R,K,H,N,Q), all colored magenta. s, small residues (S,A,C,G,D,N,P,V,T) colored green. b, big residues (L,I,F,M,W,Y,E,R,K,Q) shaded gray. Further grouping of sequences is based on the association of KilA-Nwith other domains as follows: 1, fused to KilA-C; 2, fused to D3ORF11-C; 3, fused to Mx8p63C; 4, fused to T5ORF172; 5, fused to Bro-C; 6, fused to a CCCH domain and a RING finger; 7, fused to a ring finger. (b) Structural comparison of the APSES, LAGLIDADG and tRNA splicing endonuclease (TEN) domains. The ribbon diagrams were drawn using Molscript.