The Middle Region of ROW1 Shows Substantial Sequence Similarity with Proteins of Different Functions. (A) Multiple sequence alignment of ROW1 (Amino acid 271–390) with TRX (trithorax, gene ID: 41737),31 MLL (mixed-lineage leukemia protein, gene ID: 5563643)32 and a putative rice protein (Os 04g0512400). (B) ROW1 contains a variant form of the PHD domain. Sequences framed in the box in (A) are further aligned with several characterized PHD (Cysteine4-Histidine-Cysteine3) motifs. ING2, inhibitor of growth family member 2;33 MS1, MALE STERILITY1 in Arabidopsis;34 MMD1, MALE MEIOCYTE DEATH1 in Arabidopsis;35 HAT3.1, an Arabidopsis homeobox protein;36 MLL5, human MIXED-LINEAGE LEUKEMIA5 protein;37 HOX2a, a maize homeobox gene.38 *denotes identical amino acids; ** denotes similar amino acid.