6bs8

The class 3 DnaB intein from Mycobacterium smegmatis

spinqualitylabelsall models 6bs8, resolution 1.95Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6bs8 is a 3 chain structure with sequence from "bacillus_smegmatis"_trevisan_1889 "bacillus smegmatis" trevisan 1889. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Gene: dnaB, ERS451418_06678 ("Bacillus smegmatis" Trevisan 1889) Activity: DNA helicase, with EC number 3.6.4.12 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [A0A0D6J385_MYCSM] Participates in initiation and elongation during chromosome replication; it exhibits DNA-dependent ATPase activity.[RuleBase:RU362085] Publication Abstract from PubMed 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 H2O2 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 A, 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. Mycobacterial DnaB helicase intein as oxidative stress sensor.,Kelley DS, Lennon CW, Li Z, Miller MR, Banavali NK, Li H, Belfort M Nat Commun. 2018 Oct 19;9(1):4363. doi: 10.1038/s41467-018-06554-x. PMID:30341292 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Helicase 3D structures

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