6BS8

The class 3 DnaB intein from Mycobacterium smegmatis

6BS8 の概要

• エントリーDOI: 10.2210/pdb6bs8/pdb
• 分子名称: Replicative DNA helicase (2 entities in total)
• 機能のキーワード: class 3 intein, dnab, hydrolase
• 由来する生物種: Mycobacterium smegmatis
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 43648.33

構造登録者

Li, Z.,Kelley, D.S.,Banavali, N.,Belfort, M.,Li, H. (登録日: 2017-12-01, 公開日: 2018-11-21, 最終更新日: 2024-03-13)

主引用文献

Kelley, D.S.,Lennon, C.W.,Li, Z.,Miller, M.R.,Banavali, N.K.,Li, H.,Belfort, M.
Mycobacterial DnaB helicase intein as oxidative stress sensor.
Nat Commun, 9:4363-4363, 2018

PubMed Abstract: Inteins are widespread self-splicing protein elements emerging as potential post-translational environmental sensors. Here, we describe two inteins within one protein, the Mycobacterium smegmatis replicative helicase DnaB. These inteins, DnaBi1 and DnaBi2, have homology to inteins in pathogens, splice with vastly varied rates, and are differentially responsive to environmental stressors. Whereas DnaBi1 splicing is reversibly inhibited by oxidative and nitrosative insults, DnaBi2 is not. Using a reporter that measures splicing in a native intein-containing organism and western blotting, we show that HO inhibits DnaBi1 splicing in M. smegmatis. Intriguingly, upon oxidation, the catalytic cysteine of DnaBi1 forms an intramolecular disulfide bond. We report a crystal structure of the class 3 DnaBi1 intein at 1.95 Å, supporting our findings and providing insight into this splicing mechanism. We propose that this cysteine toggle allows DnaBi1 to sense stress, pausing replication to maintain genome integrity, and then allowing splicing immediately when permissive conditions return.

PubMed: 30341292
DOI: 10.1038/s41467-018-06554-x

実験手法

X-RAY DIFFRACTION (1.95 Å)