SYRB2_PSESY Involved in the biosynthesis of syringomycin E, a cyclic lipodepsinonapeptide toxin with phytotoxic activity (PubMed:16002467, PubMed:16528784, PubMed:19245217). Catalyzes the chlorination of L-Thr to 4-Cl-L-Thr when the amino acid is tethered via a thioester linkage to a covalently bound phosphopantetheine cofactor of the carrier protein SyrB1 (L-Thr-S-SyrB1), in a reaction that requires oxygen, chloride ions, ferrous iron and 2-oxoglutarate (PubMed:16002467, PubMed:16528784, PubMed:19245217). In vitro, can catalyze tandem chlorinations at the gamma-position of the threonyl-S-protein substrate (PubMed:16528784). Can also brominate L-Thr-S-SyrB1 in reactions performed with excess sodium bromide, but a preference for chloride versus bromide by a factor of 180 can be estimated by comparing the peak intensities (PubMed:16528784). In addition, in the presence of the nitrogenous anions NO2(-) or N3(-), SyrB2 can direct aliphatic nitration and azidation reactions by the same mechanism as the native halogenation reaction (PubMed:24463698).[1][2][3][4]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
References
↑Vaillancourt FH, Yin J, Walsh CT. SyrB2 in syringomycin E biosynthesis is a nonheme FeII alpha-ketoglutarate O2-dependent halogenase. Proc Natl Acad Sci U S A. 2005 Jul 19;102(29):10111-6. PMID:16002467 doi:10.1073/pnas.0504412102
↑Vaillancourt FH, Vosburg DA, Walsh CT. Dichlorination and bromination of a threonyl-S-carrier protein by the non-heme Fe(II) halogenase SyrB2. Chembiochem. 2006 May;7(5):748-52. PMID:16528784 doi:10.1002/cbic.200500480
↑Matthews ML, Krest CM, Barr EW, Vaillancourt FH, Walsh CT, Green MT, Krebs C, Bollinger JM. Substrate-triggered formation and remarkable stability of the C-H bond-cleaving chloroferryl intermediate in the aliphatic halogenase, SyrB2. Biochemistry. 2009 May 26;48(20):4331-43. PMID:19245217 doi:10.1021/bi900109z
↑Matthews ML, Chang WC, Layne AP, Miles LA, Krebs C, Bollinger JM Jr. Direct nitration and azidation of aliphatic carbons by an iron-dependent halogenase. Nat Chem Biol. 2014 Mar;10(3):209-15. PMID:24463698 doi:10.1038/nchembio.1438
