third malignant brain tumor (MBT) repeat found in Scm-like with four MBT domains protein 1 (SFMBT1)
SFMBT1, also called renal ubiquitous protein 1, is a transcriptional repressor protein that selectively binds the N-terminal tail of histone H3 and functions as a chromatin reader in regulating epigenetic silencing and the myogenic gene program. It mediates the recruitment of corepressor complexes to target genes, followed by chromatin compaction and repression of transcription. SFMBT1 contains four MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the third MBT repeat that does not contain a semi-aromatic cage and may not bind methylated lysine residues.
Jiyao W et al.(2023). "The conserved domain database in 2023.",