(S)-3-keto-5-aminohexanoate

• 分子结构分类: 有机化合物 - 有机酸及其衍生物 - 酮酸及其衍生物
• 英文名称: (S)-3-keto-5-aminohexanoate
• 英文别名: (5S)-5-amino-3-oxohexanoate
• 化学式: C₆H₁₀NO₃
• 分子量: 144.15
• InChiKey: FAASBXNEOGMQHS-BYPYZUCNSA-M

计算性质

• 辛醇/水分配系数(LogP)：
  -2.6
• 重原子数：
  10
• 可旋转键数：
  3
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.67
• 拓扑面积：
  83.2
• 氢给体数：
  1
• 氢受体数：
  4

反应信息

• 作为反应物：
  描述：

  (S)-3-keto-5-aminohexanoate 、 乙酰辅酶A 在 3-keto-5-aminohexanoate cleavage enzyme 作用下， 生成 (S)-3-aminobutyryl-CoA 、 acetoacetic acid anion
  参考文献：
  名称：

  3-Keto-5-aminohexanoate Cleavage Enzyme

  摘要：

  The exponential increase in genome sequencing output has led to the accumulation of thousands of predicted genes lacking a proper functional annotation. Among this mass of hypothetical proteins, enzymes catalyzing new reactions or using novel ways to catalyze already known reactions might still wait to be identified. Here, we provide a structural and biochemical characterization of the 3-keto-5-aminohexanoate cleavage enzyme (Kce), an enzymatic activity long known as being involved in the anaerobic fermentation of lysine but whose catalytic mechanism has remained elusive so far. Although the enzyme shows the ubiquitous triose phosphate isomerase (TIM) barrel fold and a Zn2+ cation reminiscent of metal-dependent class II aldolases, our results based on a combination of x-ray snapshots and molecular modeling point to an unprecedented mechanism that proceeds through deprotonation of the 3-keto-5-aminohexanoate substrate, nucleophilic addition onto an incoming acetyl-CoA, intramolecular transfer of the CoA moiety, and final retro-Claisen reaction leading to acetoacetate and 3-aminobutyryl-CoA. This model also accounts for earlier observations showing the origin of carbon atoms in the products, as well as the absence of detection of any covalent acyl-enzyme intermediate. Kce is the first representative of a large family of prokaryotic hypothetical proteins, currently annotated as the "domain of unknown function" DUF849.

  DOI：

  10.1074/jbc.m111.253260

文献信息

• 3-Keto-5-aminohexanoate Cleavage Enzyme
  作者：Marco Bellinzoni、Karine Bastard、Alain Perret、Anne Zaparucha、Nadia Perchat、Carine Vergne、Tristan Wagner、Raquel C. de Melo-Minardi、François Artiguenave、Georges N. Cohen、Jean Weissenbach、Marcel Salanoubat、Pedro M. Alzari

  DOI：10.1074/jbc.m111.253260

  日期：2011.8

  The exponential increase in genome sequencing output has led to the accumulation of thousands of predicted genes lacking a proper functional annotation. Among this mass of hypothetical proteins, enzymes catalyzing new reactions or using novel ways to catalyze already known reactions might still wait to be identified. Here, we provide a structural and biochemical characterization of the 3-keto-5-aminohexanoate cleavage enzyme (Kce), an enzymatic activity long known as being involved in the anaerobic fermentation of lysine but whose catalytic mechanism has remained elusive so far. Although the enzyme shows the ubiquitous triose phosphate isomerase (TIM) barrel fold and a Zn2+ cation reminiscent of metal-dependent class II aldolases, our results based on a combination of x-ray snapshots and molecular modeling point to an unprecedented mechanism that proceeds through deprotonation of the 3-keto-5-aminohexanoate substrate, nucleophilic addition onto an incoming acetyl-CoA, intramolecular transfer of the CoA moiety, and final retro-Claisen reaction leading to acetoacetate and 3-aminobutyryl-CoA. This model also accounts for earlier observations showing the origin of carbon atoms in the products, as well as the absence of detection of any covalent acyl-enzyme intermediate. Kce is the first representative of a large family of prokaryotic hypothetical proteins, currently annotated as the "domain of unknown function" DUF849.