4X33

Structure of the Elongator cofactor complex Kti11/Kti13 at 1.45A

Summary for 4X33

• Entry DOI: 10.2210/pdb4x33/pdb
• Descriptor: Diphthamide biosynthesis protein 3, Protein ATS1, FE (III) ION, ... (7 entities in total)
• Functional Keywords: electron transfer, trna modification, complex, electron transport
• Biological source: Saccharomyces cerevisiae (Baker's yeast); More
• Cellular location: Cytoplasm : Q3E840
• Total number of polymer chains: 2
• Total formula weight: 44435.21

Authors

Kolaj-Robin, O.,McEwen, A.G.,Cavarelli, J.,Seraphin, B. (deposition date: 2014-11-27, release date: 2015-01-21, Last modification date: 2024-10-09)

Primary citation

Kolaj-Robin, O.,McEwen, A.G.,Cavarelli, J.,Seraphin, B.
Structure of the Elongator cofactor complex Kti11/Kti13 provides insight into the role of Kti13 in Elongator-dependent tRNA modification.
Febs J., 282:819-833, 2015

PubMed Abstract: Modification of wobble uridines of many eukaryotic tRNAs requires the Elongator complex, a highly conserved six-subunit eukaryotic protein assembly, as well as the Killer toxin-insensitive (Kti) proteins 11-14. Kti11 was additionally shown to be implicated in the biosynthesis of diphthamide, a post-translationally modified histidine of translation elongation factor 2. Recent data indicate that iron-bearing Kti11 functions as an electron donor to the [4Fe-4S] cluster of radical S-Adenosylmethionine enzymes, triggering the subsequent radical reaction. We show here that recombinant yeast Kti11 forms a stable 1 : 1 complex with Kti13. To obtain insights into the function of this heterodimer, the Kti11/Kti13 complex was purified to homogeneity, crystallized, and its structure determined at 1.45 Å resolution. The importance of several residues mediating complex formation was confirmed by mutagenesis. Kti13 adopts a fold characteristic of RCC1-like proteins. The seven-bladed β-propeller consists of a unique mixture of four- and three-stranded blades. In the complex, Kti13 orients Kti11 and restricts access to its electron-carrying iron atom, constraining the electron transfer capacity of Kti11. Based on these findings, we propose a role for Kti13, and discuss the possible functional implications of complex formation.

PubMed: 25604895
DOI: 10.1111/febs.13199

Experimental method

X-RAY DIFFRACTION (1.45 Å)