title: MauG-dependent in vitro biosynthesis of tryptophan tryptophylquinone in methylamine dehydrogenase.
abstract: Tryptophan tryptophylquinone (TTQ) is the prosthetic group of methylamine dehydrogenase (MADH) and is synthesized through post-translational modification of two endogenous tryptophan residues. This modification involves two oxygenation reactions and one cross-linking reaction. It is clearly shown that the incorporation of the second oxygen into betaTrp57 and the covalent cross-linking of betaTrp57 to betaTrp108 are MauG-dependent processes. These reaction steps are severely compromised in vivo when mauG is mutated or deleted. These steps may then be catalyzed in vitro upon addition of MauG to the isolated biosynthetic intermediates. These results also show that TTQ formation is linked to proper assembly of subunits during MADH biosynthesis. Last, these results demonstrate a novel function for the c-type heme protein, MauG, which is consistent with its atypical physical properties. These results are the first description of an enzyme-mediated biosynthesis of a protein-derived cofactor in vitro.
authors.affiliation: Department of Biochemistry, The University of Mississippi Medical Center, Jackson, MS 39216, USA.
authors.forename: Yongting
authors.initials: Y
authors.lastname: Wang
authors.forename: Xianghui
authors.initials: X
authors.lastname: Li
authors.forename: Limei H
authors.initials: LH
authors.lastname: Jones
authors.forename: Arwen R
authors.initials: AR
authors.lastname: Pearson
authors.forename: Carrie M
authors.initials: CM
authors.lastname: Wilmot
authors.forename: Victor L
authors.initials: VL
authors.lastname: Davidson
mesh_terms: D006420:Hemeproteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D045563:Indolequinones / Q000096:biosynthesis* / Q000235:genetics; D013058:Mass Spectrometry; D016297:Mutagenesis, Site-Directed; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000096:biosynthesis* / Q000235:genetics; D010231:Paracoccus denitrificans / Q000201:enzymology / Q000235:genetics; D014364:Tryptophan / Q000031:analogs & derivatives* / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D006420:Hemeproteins; D045563:Indolequinones; C070569:tryptophan tryptophylquinone; D014364:Tryptophan; C021567:methylamine dehydrogenase; D000587:Oxidoreductases Acting on CH-NH Group Donors