Genome-Wide Identification, Evolutionary, and Expression Analyses of Histone H3 Variants in Plants

Figure 2

Alignment of Arabidopsis, rice, and maize HTR proteins. The signature positions 31, 41, 87, and 90 to distinguish H3.1 and H3.3 are marked. All H3.1 are absence of introns and signature positions are A₃₁F₄₁S₈₇A₉₀. All H3.3 contain introns and signature positions are T₃₁Y₄₁H₈₇L₉₀. H3-like genes all deviate from H3.1 and H3.3 at positions 31, 41, 87, and 90 and are the presence or absence of introns. The K4, K9, K27, and K36 commonly involved in histone methylations are highly conserved in H3.1 and H3.3. Amino acid substitutions are colored in red (H3.1 and H3.3) and purple (H3-like).