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Publication Abstract from PubMed

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 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 A. Trf is composed of an N-terminal rubredoxin-like domain containing a bound zinc ion and a C-terminal OB-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 - e. g. the Sso2064 protein from Sulfolobus solfataricus, as well as to scaffold proteins found in the acetoacetyl-CoA thiolase/HMG-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.

Crystal structure of the translation recovery factor Trf from Sulfolobus solfataricus.,Kaiser M, Wurm JP, Martens B, Blasi U, Pogoryelov D, Wohnert J FEBS Open Bio. 2019 Dec 5. doi: 10.1002/2211-5463.12772. PMID:31804766^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.