2a8k

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spinqualitylabelsall models PDB ID 2a8k Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image
, resolution 1.5Å
Ligands:
Gene:	col (Escherichia coli)
Coordinates:	save as pdb, mmCIF, xml

Structural and Mutational Studies of the Catalytic Domain of Colicin E5a tRNA-Specific Ribonuclease

Overview

Colicin E5 specifically cleaves four tRNAs in Escherichia coli that contain the modified nucleotide queuosine (Q) at the wobble position, thereby preventing protein synthesis and ultimately resulting in cell death. Here, the crystal structure of the catalytic domain of colicin E5 (E5-CRD) from E. coli was determined at 1.5 A resolution. Unexpectedly, E5-CRD adopts a core folding with a four-stranded beta-sheet packed against an alpha-helix, seen in the well-studied ribonuclease T1 despite a lack of sequence similarity. Beyond the core catalytic domain, an N-terminal helix, a C-terminal beta-strand and loop, and an extended internal loop constitute an RNA binding cleft. Mutational analysis identified five amino acids that were important for tRNA substrate binding and cleavage by E5-CRD. The structure, together with the mutational study, allows us to propose a model of colicin E5-tRNA interactions, suggesting the molecular basis of tRNA substrate recognition and the mechanism of tRNA cleavage by colicin E5.

About this Structure

2A8K is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.

Reference

Structural and mutational studies of the catalytic domain of colicin E5: a tRNA-specific ribonuclease., Lin YL, Elias Y, Huang RH, Biochemistry. 2005 Aug 9;44(31):10494-500. PMID:16060658

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