One of the three domains of kinetoplastid NADH:fumarate oxidoreductase (FRD) is homologous to bacterial flavin transferase that catalyzes transfer of FMN residue from FAD to threonine in flavoproteins. Leptomonas pyrrhocoris FRD produced in yeast cells, which lack flavin transferase gene in their proteome, reduces fumarate in the presence of NADH and contains an FMN residue covalently linked to a Ser9 residue. The conserved flavinylation motif of FRD, D₃(g/s)x(s/t)(s/g)AS₉, is similar to the Dxx(s/t)gAT motif recognized by flavin transferase in prokaryotic proteins. Ser9 replacement abolished the flavinylation and fumarate reductase activity of FRD. These findings suggest that the flavinylation is important for the activity of FRD and that this post-translational modification is carried out by the own flavin transferase domain.

动素体NADH：富马酸酯氧化还原酶（FRD）的三个域之一与细菌黄素转移酶同源，后者催化黄素蛋白中FMN残基从FAD转移到苏氨酸。在蛋白质组中缺少黄素转移酶基因的酵母细胞中产生的焦单核小球菌FRD，在存在NADH的情况下降低了富马酸酯，并含有与Ser9残基共价连接的FMN残基。FRD，D ₃（g / s）x（s / t）（s / g）AS ₉的保守黄素化基序类似于原核蛋白中黄素转移酶识别的Dxx（s / t）gAT基序。Ser9替代取消了FRD的黄素酰化和富马酸酯还原酶活性。这些发现表明黄素酰化对于FRD的活性是重要的，并且这种翻译后修饰是通过自身的黄素转移酶结构域进行的。