| Primary Identifier | IPR039994 | Type | Family |
| Short Name | JmjC_protein |
| description | This entry includes proteins with a JmjC domain. Proteins are bifunctional, acting as histone lysine demethylases and ribosomal histidine hydroxylases. Proteins include:Bifunctional lysine-specific demethylase and histidyl-hydroxylase NO66 (also known as Jumanjic domain protein 1) [].Ribosomal oxygenase 1 (also known as ribosomal oxygenase NO66), which specifically demethylates 'Lys-4' (H3K4me) and 'Lys-36' (H3K36me) of histone H3 [].Ribosomal oxygenase 2, which demethylates trimethylated 'Lys-9' on histone H3 (H3K9me3), leading to an increase in ribosomal RNA expression []. It also hydroxylates 60S ribosomal protein L27a on 'His-39' [].50S ribosomal protein L16 3-hydroxylase from Escherichia coli, which catalyzes the hydroxylation of 50S ribosomal protein L16 on 'Arg-81' [].The JmjN and JmjC domains are two non-adjacent domains which have been identified in the jumonji family of transcription factors. Although it was originally suggested that the JmjN and JmjC domains always co-occur and might form a single functional unit within the folded protein, the JmjC domain was later found without the JmjN domain in organisms from bacteria to human [, , ].Proteins containing JmjC domain are predicted to be metalloenzymes that adopt the cupin fold and are candidates for enzymes that regulate chromatin remodelling []. The cupin fold is a flattened β-barrel structure containing two sheets of five antiparallel β-strands that form the walls of a zinc-binding cleft. Based on the crystal structure of JmjC domain containing protein FIH and JHDM3A/JMJD2A, the JmjC domain forms an enzymatically active pocket that coordinates Fe(III) and alphaKG. Three amino-acid residues within the JmjC domain bind to the Fe(II) cofactor and two additional residues bind to alphaKG []. JmjC domains were identified in numerous eukaryotic proteins containing domains typical of transcription factors, such as PHD, C2H2, ARID/BRIGHT and zinc fingers [, ]. The JmjC has been shown to function in a histone demethylation mechanism that is conserved from yeast to human []. JmjC domain proteins may be protein hydroxylases that catalyse a novel histone modification []. The human JmjC protein named Tyw5p unexpectedly acts in the biosynthesis of a hypermodified nucleoside, hydroxy-wybutosine, in tRNA-Phe by catalysing hydroxylation []. |
