Roseoflavin(1-)

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 蝶啶及其衍生物
• 英文名称: Roseoflavin(1-)
• 英文别名: 8-(dimethylamino)-7-methyl-4-oxo-10-[(2S,3S,4R)-2,3,4,5-tetrahydroxypentyl]benzo[g]pteridin-2-olate
• 化学式: C18H22N5O6-
• 分子量: 404.4
• InChiKey: IGQLDUYTWDABFK-GUTXKFCHSA-M

计算性质

• 辛醇/水分配系数(LogP)：
  -0.7
• 重原子数：
  29
• 可旋转键数：
  6
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.44
• 拓扑面积：
  165
• 氢给体数：
  4
• 氢受体数：
  8

反应信息

• 作为产物：
  描述：

  8-amino-8-demethylriboflavin 、 S-腺苷蛋氨酸 生成 氢(+1)阳离子 、 Roseoflavin(1-) 、 S-(5'-腺苷)-L-高半胱氨酸
  参考文献：
  名称：

  RosA的结构和动力学研究，该酶催化8-demethyl-8-氨基-D-核黄素甲基化为抗生素玫瑰黄素。

  摘要：

  N，N-8-去甲基-8-氨基-D-核黄素二甲基转移酶（RosA）催化8脱甲基-8-氨基-D-核黄素（AF）在达维链霉菌中的最终的二甲基化成抗生素玫瑰黄素（RoF）。在本研究中，我们已经解决了RosA的X射线结构，并确定了底物和产品的结合特性。此外，我们使用稳态和快速反应动力学来获得有关反应机理的详细信息。发现RosA的结构类似于先前确定的S-腺苷甲硫氨酸（SAM）依赖性甲基转移酶，其特征在于两个结构域，主要是α-螺旋“正交束”和Rossmann-样结构域（α/β扭曲的开孔）。生物信息学和分子建模使我们能够预测RosA中潜在的SAM和AF结合位点，这表明两种底物，AF和SAM可以独立绑定到各自的绑定袋。动力学实验证实了这一点，该实验证明了随机顺序的bi-bi反应机理。此外，我们已经通过等温滴定量热法或UV-Vis吸收光谱法确定了底物和产物的解离常数。这表明与底物AF和SAM相比，RoF和S-

  DOI：

  10.1111/febs.13690

文献信息

• A Novel N,N-8-Amino-8-demethyl-d-riboflavin Dimethyltransferase (RosA) Catalyzing the Two Terminal Steps of Roseoflavin Biosynthesis in Streptomyces davawensis
  作者：Frank Jankowitsch、Christian Kühm、Roland Kellner、Jörn Kalinowski、Stefan Pelzer、Peter Macheroux、Matthias Mack

  DOI：10.1074/jbc.m111.292300

  日期：2011.11

  Streptomyces davawensis synthesizes the antibiotic roseoflavin (RoF) (8-dimethylamino-8-demethyl-D-riboflavin). It was postulated that RoF is synthesized from riboflavin via 8-amino( AF) and 8-methylamino-8-demethyl-D-riboflavin (MAF). In a cell-free extract of S. davawensis, an S-adenosyl methionine-dependent conversion of AF into MAF and RoF was observed. The corresponding N,N-8-amino-8-demethyl-D-riboflavin dimethyltransferase activity was enriched by column chromatography. The final most active fraction still contained at least five different proteins that were analyzed by enzymatic digestion and concomitant de novo sequencing by MS/MS. One of the sequences matched a hypothetical peptide fragment derived from an as yet uncharacterized open reading frame (sda77220) located in the middle of a (putative) gene cluster within the S. davawensis genome. Expression of ORF sda77220 in Escherichia coli revealed that the corresponding gene product had N,N-8-amino-8-demethyl-D-riboflavin dimethyltransferase activity. Inactivation of ORF sda77220 led to a S. davawensis strain that synthesized AF but not MAF or RoF. Accordingly, as the first identified gene of RoF biosynthesis, ORF sda77220 was named rosA. RosA (347 amino acids; 38 kDa) was purified from a recombinant E. coli strain (as a His(6)-tagged protein) and was biochemically characterized (apparent K-m for AF = 57.7 +/- 9.2 mu M; apparent K-D for AF = 10.0 mu M; k(cat) = 0.37 +/- 0.02 s(-1)). RosA is a unique enzyme and may be useful for a variety of applications.