zinc finger-binding (ZnB) and C2H2-type zinc finger (Zn) domain found in suppressor of zeste 12 protein (SUZ12), and similar proteins
This family includes a group of Polycomb group (PcG) proteins from metazoa and plants, such as suppressor of zeste 12 protein (SUZ12), and Polycomb group proteins EMBRYONIC FLOWER 2 (EMF2) and FERTILIZATION-INDEPENDENT SEED 2 (FIS2). SUZ12 (also called chromatin precipitated E2F target 9 protein (ChET 9 protein), or joined to JAZF1 protein) is a component of the Polycomb Repressive Complex 2 (PRC2)/EED-EZH2 complex, which methylates 'Lys-9' (H3K9me) and 'Lys-27' (H3K27me) of histone H3, leading to transcriptional repression of the affected target gene. The PRC2/EED-EZH2 complex may also serve as a recruiting platform for DNA methyltransferases, thereby linking two epigenetic repression systems. EMF2 is involved in flowering processes by repressing unknown target genes and preventing reproductive development. It participates in polycomb group (PcG) protein complex-mediated (probably in complex with EMF1) silencing of the flower homeotic genes AGAMOUS (AG), PISTILLATA (PI), and APETALA3 (AP3), as well as of some regulatory genes such as ABSCISIC ACID INSENSITIVE3 (ABI3), LONG VEGETATIVE PHASE1 (LOV1), and FLOWERING LOCUS C (FLC) during vegetative development, by mediating trimethylation of histone 3 lysine 27 on the AG chromatin (H3K27me3). FIS2 is required to prevent the proliferation of the central cell by repressing unknown target genes before fertilization. It regulates the anteroposterior organization of the endosperm. Members in this family contain a unique structural ZnB-Zn platform consisting of zinc finger-binding (ZnB) and C2H2-type zinc finger (Zn).
Jiyao W et al.(2023). "The conserved domain database in 2023.",