Shu Hung-Yu, Lin Guang-Huey, Wu Ying-Chung, Tschen Johannes Scheng-Ming, Liu Shih-Tung
Graduate Institute of Microbiology and Immunology, National Yang-Ming University, Shih-Pai, Taipei, 112, Taiwan.
Biochem Biophys Res Commun. 2002 Apr 12;292(4):789-93. doi: 10.1006/bbrc.2002.6729.
Fengycin is a lipopeptidic antibiotic produced nonribosomally by Bacillus subtilis F29-3. Synthesis of this antibiotic requires five fengycin synthetases encoded by fenC, fenD, fenE, fenA, and fenB. In this study, we analyze the functions of the enzyme encoded by fenE, which contains two amino acid activation modules, FenE1 and FenE2. ATP-PP(i) exchange assay revealed that FenE1 activates l-Glu and FenE2 activates l-Ala, l-Val, and l-2-aminobutyric acid, indicating that FenE activates the fifth and the sixth amino acids in fengycin. Furthermore, l-Val is a better substrate than l-Ala for FenE2 in vitro, explaining why B. subtilis F29-3 normally produces twice as much of fengycin B than fengycin A, which contains d-Val and d-Ala at the sixth amino acid position, respectively. Results presented herein suggest that fengycin synthetase genes and amino acids in fengycin are colinear.
丰原素是由枯草芽孢杆菌F29-3非核糖体合成产生的一种脂肽类抗生素。这种抗生素的合成需要由fenC、fenD、fenE、fenA和fenB编码的五种丰原素合成酶。在本研究中，我们分析了由fenE编码的酶的功能，该酶包含两个氨基酸激活模块，即FenE1和FenE2。ATP-PP(i)交换试验表明，FenE1激活L-谷氨酸，FenE2激活L-丙氨酸、L-缬氨酸和L-2-氨基丁酸，这表明FenE激活了丰原素中的第五和第六个氨基酸。此外，在体外，L-缬氨酸是FenE2比L-丙氨酸更好的底物，这解释了为什么枯草芽孢杆菌F29-3通常产生的丰原素B是丰原素A的两倍，丰原素A在第六个氨基酸位置分别含有D-缬氨酸和D-丙氨酸。本文给出的结果表明，丰原素合成酶基因和丰原素中的氨基酸是共线的。
