Polynucleotide kinase that can phosphorylate the 5'-hydroxyl groups of single-stranded and double-stranded RNA and DNA substrates (PubMed:21063389). Involved in rRNA processing and its kinase activity is required for the processing of the 32S precursor into 5.8S and 28S rRNAs, more specifically for the generation of the major 5.8S(S) form (PubMed:21063389). Required for the efficient pre-rRNA processing of internal transcribed spacer 2 (ITS2) (PubMed:21063389). Associates with LAS1L to form an ITS2 pre-rRNA endonuclease-kinase complex and is responsible for the transport of this complex into the nucleolus (PubMed:31288032). {ECO:0000269|PubMed:21063389, ECO:0000269|PubMed:31288032}. This is the function of NOL9 (nucleolar protein 9, Ensembl gene identifier ENSG00000162408).