7lc5

Crystal structure of epoxyqueuosine reductase QueH from Thermotoga maritimaCrystal structure of epoxyqueuosine reductase QueH from Thermotoga maritima

Structural highlights 7lc5 is a 1 chain structure with sequence from Thermotoga maritima MSB8. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.5Å Ligands: , , Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function QUEH_THEMA Catalyzes the conversion of epoxyqueuosine (oQ) to queuosine (Q), which is a hypermodified base found in the wobble positions of tRNA(Asp), tRNA(Asn), tRNA(His) and tRNA(Tyr).[HAMAP-Rule:MF_02089] Publication Abstract from PubMed Queuosine is a structurally unique and functionally important tRNA modification, widely distributed in eukaryotes and bacteria. The final step of queuosine biosynthesis is the reduction/deoxygenation of epoxyqueuosine to form the cyclopentene motif of the nucleobase. The chemistry is performed by the structurally and functionally characterized cobalamin-dependent QueG. However, the queG gene is absent from several bacteria that otherwise retain queuosine biosynthesis machinery. Members of the IPR003828 family (previously known as DUF208) have been recently identified as nonorthologous replacements of QueG, and this family was renamed QueH. Here, we present the structural characterization of QueH from Thermotoga maritima. The structure reveals an unusual active site architecture with a [4Fe-4S] metallocluster along with an adjacent coordinated iron metal. The juxtaposition of the cofactor and coordinated metal ion predicts a unique mechanism for a two-electron reduction/deoxygenation of epoxyqueuosine. To support the structural characterization, in vitro biochemical and genomic analyses are presented. Overall, this work reveals new diversity in the chemistry of iron/sulfur-dependent enzymes and novel insight into the last step of this widely conserved tRNA modification. Epoxyqueuosine Reductase QueH in the Biosynthetic Pathway to tRNA Queuosine Is a Unique Metalloenzyme.,Li Q, Zallot R, MacTavish BS, Montoya A, Payan DJ, Hu Y, Gerlt JA, Angerhofer A, de Crecy-Lagard V, Bruner SD Biochemistry. 2021 Oct 26;60(42):3152-3161. doi: 10.1021/acs.biochem.1c00164., Epub 2021 Oct 15. PMID:34652139 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

spinqualitylabelsall models 7lc5, resolution 1.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image