TY - JOUR A1 - Kaiser, Marco A1 - Wurm, Jan Philip A1 - Märtens, Birgit A1 - Bläsi, Udo A1 - Pogoryelov, Denys A1 - Wöhnert, Jens T1 - Crystal structure of the translation recovery factor Trf from Sulfolobus solfataricus T2 - FEBS Open Bio N2 - During translation initiation, the heterotrimeric archaeal translation initiation factor 2 (aIF2) recruits the initiator tRNAi to the small ribosomal subunit. In the stationary growth phase and/or during nutrient stress, Sulfolobus solfataricus aIF2 has a second function: It protects leaderless mRNAs against degradation by binding to their 5′‐ends. The S. solfataricus protein Sso2509 is a translation recovery factor (Trf) that interacts with aIF2 and is responsible for the release of aIF2 from bound mRNAs, thereby enabling translation re‐initiation. It is a member of the domain of unknown function 35 (DUF35) protein family and is conserved in Sulfolobales as well as in other archaea. Here, we present the X‐ray structure of S. solfataricus Trf solved to a resolution of 1.65 Å. Trf is composed of an N‐terminal rubredoxin‐like domain containing a bound zinc ion and a C‐terminal oligosaccharide/oligonucleotide binding fold domain. The Trf structure reveals putative mRNA binding sites in both domains. Surprisingly, the Trf protein is structurally but not sequentially very similar to proteins linked to acyl‐CoA utilization—for example, the Sso2064 protein from S. solfataricus—as well as to scaffold proteins found in the acetoacetyl‐CoA thiolase/high‐mobility group‐CoA synthase complex of the archaeon Methanothermococcus thermolithotrophicus and in a steroid side‐chain‐cleaving aldolase complex from the bacterium Thermomonospora curvata. This suggests that members of the DUF35 protein family are able to act as scaffolding and binding proteins in a wide variety of biological processes. KW - DUF35 KW - ribosome KW - Sulfolobus solfataricus KW - translation initiation KW - translation recovery factor Trf Y1 - 2019 UR - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/56056 UR - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-560564 SN - 2211-5463 VL - 10.2020 IS - 2 SP - 221 EP - 228 PB - Wiley CY - Hoboken, NJ ER -