EC	1.14.13.187
Accepted name:	L-evernosamine nitrososynthase
Reaction:	dTDP-β-L-evernosamine + 2 NADPH + 2 H+ + 2 O2 = dTDP-2,3,6-trideoxy-3-C-methyl-4-O-methyl-3-nitroso-β-L-arabino-hexopyranose + 2 NADP+ + 3 H2O (overall reaction) (1a) dTDP-β-L-evernosamine + NADPH + H+ + O2 = dTDP-N-hydroxy-β-L-evernosamine + NADP+ + H2O (1b) dTDP-N-hydroxy-β-L-evernosamine + NADPH + H+ + O2 = dTDP-2,3,6-trideoxy-3-C-methyl-4-O-methyl-3-nitroso-β-L-arabino-hexopyranose + NADP+ + 2 H2O
Glossary:	dTDP-β-L-evernosamine = dTDP-3-amino-2,3,6-trideoxy-3-C-methyl-4-O-methyl-β-L-arabino-hexopyranose dTDP-β-L-evernitrose = dTDP-2,3,6-trideoxy-3-C-methyl-4-O-methyl-3-nitro-β-L-arabino-hexopyranose
Systematic name:	dTDP-β-L-evernosamine,NADPH:oxygen oxidoreductase (N-hydroxylating)
Comments:	Requires FAD. Isolated from the bacterium Micromonospora carbonacea var. africana. The nitroso group is probably spontaneously oxidized to a nitro group giving dTDP-β-L-evernitrose, which is involved in the biosynthesis of the antibiotic everninomycin. The reaction was studied using dTDP-β-L-4-epi-vancosamine (dTDP-4-O-desmethyl-β-L-evernitrosamine).
References:	1.  Hu, Y., Al-Mestarihi, A., Grimes, C.L., Kahne, D. and Bachmann, B.O. A unifying nitrososynthase involved in nitrosugar biosynthesis. J. Am. Chem. Soc. 130 (2008) 15756–15757. [PMID: 18983146] 2.  Vey, J.L., Al-Mestarihi, A., Hu, Y., Funk, M.A., Bachmann, B.O. and Iverson, T.M. Structure and mechanism of ORF36, an amino sugar oxidizing enzyme in everninomicin biosynthesis. Biochemistry 49 (2010) 9306–9317. [PMID: 20866105]
[EC 1.14.13.187 created 2014]
EC	2.4.1.311
Accepted name:	chloroorienticin B synthase
Reaction:	dTDP-β-L-4-epi-vancosamine + desvancosaminyl-vancomycin = dTDP + chloroorienticin B
Glossary:	dTDP-β-L-4-epi-vancosamine = dTDP-3-amino-2,3,6-trideoxy-3-methyl-β-L-arabino-hexopyranose desvancosaminyl-vancomycin = vanomycin pseudoaglycone
Other name(s):	GtfA
Systematic name:	dTDP-L-4-epi-vancosamine:desvancosaminyl-vancomycin vancosaminyltransferase
Comments:	The enzyme from the bacterium Amycolatopsis orientalis is involved in the biosynthesis of the glycopeptide antibiotic chloroeremomycin.
References:	1.  Mulichak, A.M., Losey, H.C., Lu, W., Wawrzak, Z., Walsh, C.T. and Garavito, R.M. Structure of the TDP-epi-vancosaminyltransferase GtfA from the chloroeremomycin biosynthetic pathway. Proc. Natl. Acad. Sci. USA 100 (2003) 9238–9243. [PMID: 12874381] 2.  Lu, W., Oberthur, M., Leimkuhler, C., Tao, J., Kahne, D. and Walsh, C.T. Characterization of a regiospecific epivancosaminyl transferase GtfA and enzymatic reconstitution of the antibiotic chloroeremomycin. Proc. Natl. Acad. Sci. USA 101 (2004) 4390–4395. [PMID: 15070728]
[EC 2.4.1.311 created 2013]