Figure 1.

Structures of chromodomains from the HP1 protein (Drosophila melanogaster; pdb:1q3l)⁴ and PpatensLTR1 (Gypsy LTR retrotransposon from moss Physcomitrella patens) (A); and multiple alignment of ‘classical’ chromodomains and ‘shadow’ chromo-like motifs from functional proteins as well as group I and group II Gypsy LTR retrotransposon chromodomains (B). The PpatensLTR1 chromodomain structure was predicted by (PS)2.⁵ The residues that constitute the aromatic pocket are indicated by arrows at the top. The secondary structural elements are shown at the bottom: arrows indicate β-strands; cylinder indicates α-helix. The GenBank accession numbers for the sequences are as follows: DmHP1—M57574; DmPc—P26017; MoMOD1 and MoMOD1scdv—P23197; hSUV39H1—S47004; HsHP1scd—AAB26994; DmMi2-2—AF119716; MAGGY—L35053; MGRL3—AF314096; Pyret—AB062507; Cft1—AF051915; PpatensLTR1—XM_001752430; sr35—AC068924; rn8—AK068625; RIRE3—AC119148; Tekay—AF050455; RetroSor2—AF061282; Tma—AF147263.