chromo barrel domain of human male-specific lethal complex subunit 3, and similar proteins
This subgroup includes human male-specific lethal (MSL) complex subunit 3 (MSL3, also known as MSL3L1). The MSL3 chromodomain specifically recognizes the H4K20 monomethyl mark, in a DNA-dependent manner, and may be involved in chromosomal targeting of the MSL complex. Also included is MORF-related gene on chromosome 15 (MRG15, also known as MORF4L1) which specifically binds to Lys36-methylated histone H3 and plays a role in transcriptional regulation and in DNA repair. This subgroup also includes Arabidopsis thaliana Morf Related Gene 2 (MRG2) which acts as a H3K4me3/H3K36me3 reader involved in the regulation of Arabidopsis flowering. SH3-fold-beta-barrel domains of the chromo-like superfamily include chromodomains, chromo shadow domains and chromo barrel domains, and are implicated in the recognition of lysine-methylated histone tails and nucleic acids. The chromodomain differs, in that it lacks the first strand of the SH3-fold-beta-barrel. This first strand is altered by insertion in the chromo shadow domains, and chromo barrel domains are typical SH3-fold-beta-barrel domains with sequence similarity to the canonical chromo domain.