InterPro domain: IPR013926

This entry represents the EKC/KEOPS complex subunit Cgi121 from fungi and its homologue, TPRKB from mammals. This entry also includes archaeal homologues [ 1 ].

CGI121 is part of the KEOPS complex, which is required for the formation of a threonylcarbamoyl group on adenosine at position 37 (t6A37) in tRNAs that read codons beginning with adenine [ 2 ]. The KEOPS complex also plays an important part in telomere uncapping and telomere elongation and is required for efficient recruitment of transcriptional coactivators [ 3 ].

TPRKB has been shown to bind to the p53-related protein kinase (PRPK) [ 4 ]. PRPK is a novel protein kinase which binds to and induces phosphorylation of the tumour suppressor protein p53.

1. Atomic structure of the KEOPS complex: an ancient protein kinase-containing molecular machine. Mol. Cell 32, 259-75
2. The highly conserved KEOPS/EKC complex is essential for a universal tRNA modification, t6A. EMBO J. 30, 873-81
3. A genome-wide screen identifies the evolutionarily conserved KEOPS complex as a telomere regulator. Cell 124, 1155-68
4. Identification of CGI-121, a novel PRPK (p53-related protein kinase)-binding protein. Biochem. Biophys. Res. Commun. 303, 399-405