Blanc V, Gil P, Bamas-Jacques N, Lorenzon S, Zagorec M, Schleuniger J, Bisch D, Blanche F, Debussche L, Crouzet J, Thibaut D
Division Recherche Pharmaceutique, Centre de Recherche de Vitry-Alfortville, Vitry sur Seine, France.
Mol Microbiol. 1997 Jan;23(2):191-202. doi: 10.1046/j.1365-2958.1997.2031574.x.
Four pap genes (papA, papB, papC, papM) were found by sequencing near to snbA, a Streptomyces pristinaespiralis gene which was previously shown to encode one of the pristinamycin I (PI) synthetases. Analysis of the homologies observed from the deduced amino acid sequences suggested that these four genes could be involved in the biosynthesis of the PI precursor 4-dimethylamino-L-phenylalanine (DMPAPA). This was first verified when disruption of papA in S. pristinaespiralis led to a PI- phenotype, which was reversed by the addition of DMPAPA into the culture medium. Further confirmation was obtained when papM was overexpressed in Escherichia coli and the corresponding protein purified to homogeneity. It catalysed the two successive N-methylation steps of 4-amino-L-phenylalanine leading to DMPAPA via 4-methylamino-L-phenylalanine. These results allowed us to assign a function to each of the four pap genes and to propose a biosynthetic pathway for DMPAPA.
通过测序发现，在链霉菌属的螺旋霉素基因snbA附近存在四个pap基因（papA、papB、papC、papM），snbA基因先前已被证明可编码普那霉素I（PI）合成酶之一。对推导的氨基酸序列进行同源性分析表明，这四个基因可能参与PI前体4-二甲基氨基-L-苯丙氨酸（DMPAPA）的生物合成。当螺旋链霉菌中的papA被破坏导致PI-表型时，这一点首先得到验证，而向培养基中添加DMPAPA可逆转该表型。当papM在大肠杆菌中过表达且相应蛋白质被纯化至同质时，进一步证实了这一点。它催化4-氨基-L-苯丙氨酸的两个连续N-甲基化步骤，通过4-甲基氨基-L-苯丙氨酸生成DMPAPA。这些结果使我们能够为四个pap基因中的每一个赋予功能，并提出DMPAPA的生物合成途径。
