2A8K

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

2A8K の概要

• エントリーDOI: 10.2210/pdb2a8k/pdb
• 分子名称: Colicin E5, CALCIUM ION (3 entities in total)
• 機能のキーワード: ribonuclease, toxin, hydrolase
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 48145.59

構造登録者

Lin, Y.L.,Elias, Y.,Huang, R.H. (登録日: 2005-07-08, 公開日: 2005-09-20, 最終更新日: 2024-02-14)

主引用文献

Lin, Y.L.,Elias, Y.,Huang, R.H.
Structural and mutational studies of the catalytic domain of colicin E5: A tRNA-specific ribonuclease
Biochemistry, 44:10494-10500, 2005

PubMed Abstract: 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.

PubMed: 16060658
DOI: 10.1021/bi050749s

実験手法

X-RAY DIFFRACTION (1.5 Å)