Oxygenase that can act as both a histone lysine demethylase and a ribosomal histidine hydroxylase. Is involved in the demethylation of trimethylated 'Lys-9' on histone H3 (H3K9me3), leading to an increase in ribosomal RNA expression. Also catalyzes the hydroxylation of 60S ribosomal protein L27a on 'His-39'. May play an important role in cell growth and survival. May be involved in ribosome biogenesis, most likely during the assembly process of pre-ribosomal particles. 2-oxoglutarate + L-histidyl-[ribosomal protein uL15] + O2 = (3S)-3-hydroxy-L-histidyl-[ribosomal protein uL15] + CO2 + succinate Binds 1 Fe(2+) ion per subunit. Expressed in liver, skeletal muscle, heart, pancreas, and placenta. Not detected in brain, lung or kidney. Expressed in several lung cancer tissues, but is barely detected in the adjacent non-cancerous tissues. Also highly expressed in several esophageal squamous cell carcinoma (ESCC), and colon cancer tissues, and in various cancer cell lines. Up-regulated in response to MYC, in alveolar macrophages from coal miners and in silica particle-treated A549 lung cancer cells. Belongs to the ROX family. MINA53 subfamily. Truncated C-terminus.