Plays an essential role in facilitating the proper assembly of the mitochondrial large ribosomal subunit and its helicase activity is essential for this function (PubMed:25683708, PubMed:25683715). May be involved in RNA processing or transport. Has RNA and Mg(2+)- dependent ATPase activity (PubMed:11350955). {ECO:0000269|PubMed:11350955, ECO:0000269|PubMed:25683708, ECO:0000269|PubMed:25683715}. This is the function of Ensembl gene identifier ENSG00000182810 (DDX28, DEAD-box helicase 28).