A paralog of Pcc1 is the fifth core subunit of the KEOPS tRNA-modifying complex in Archaea.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36720870.
- Also identified by DOI 10.1038/s41467-023-36210-y and PMC identifier 9889334.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
In Archaea and Eukaryotes, the synthesis of a universal tRNA modification, N<sup>6</sup>-threonyl-carbamoyl adenosine (t<sup>6</sup>A), is catalyzed by the KEOPS complex composed of Kae1, Bud32, Cgi121, and Pcc1. A fifth subunit, Gon7, is found only in Fungi and Metazoa. Here, we identify and characterize a fifth KEOPS subunit in Archaea. This protein, dubbed Pcc2, is a paralog of Pcc1 and is widely conserved in Archaea. Pcc1 and Pcc2 form a heterodimer in solution, and show modest sequence conservation but very high structural similarity. The five-subunit archaeal KEOPS does not form dimers but retains robust tRNA binding and t<sup>6</sup>A synthetic activity. Pcc2 can substitute for Pcc1 but the resulting KEOPS complex is inactive, suggesting a distinct function for the two paralogs. Comparative sequence and structure analyses point to a possible evolutionary link between archaeal Pcc2 and eukaryotic Gon7. Our work indicates that Pcc2 regulates the oligomeric state of the KEOPS complex, a feature that seems to be conserved from Archaea to Eukaryotes.
Medical subject headings
- Adenosine
- Archaea