Inactivation of gilGT, encoding a C-glycosyltransferase, and gilOlll, encoding a p450 enzyme, allows the details of the late biosynthetic pathway to gilvocarcin V to be delineated
Inactivation of gilGT, encoding a C-glycosyltransferase, and gilOlll, encoding a p450 enzyme, allows the details of the late biosynthetic pathway to gilvocarcin V to be delineated
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DOI：
10.1002/cbic.200600031
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发表时间：
2006-07-01
期刊：
影响因子：
3.2
通讯作者：
Rohr, Jurgen
中科院分区：
文献类型：
--
作者：
Liu, Tao;Kharel, Madan Kumar;Rohr, Jurgen
gilGT基因，它编码一个假定的糖基转移酶（GT），是495个氨基酸（aa）长，从灰色链霉菌Go 3592 gilvocarcin V（GV）基因簇，重新测序显示，以前报道的gilGT确实包含两个基因。这些是大的gilGT，其编码C-糖基转移酶GilGT（379 aa），和较小的gilV基因，其编码未知功能的酶（116 aa）。gilV基因位于GV基因簇中gilGT的上游。gilGT的框内缺失产生了积累defucogilvocarcin E（defuco-GE）的突变体。结果证明了GilGT作为C-糖基转移酶的功能。缺失gilOIII，其位于gilGT的下游，导致积累gilvocarcin E（GE）的突变体。这证实了相应的P450酶GilOIII参与GV的乙烯基形成。将GE、defuco-GE和defucogilvocarcin V（defuco-GV）喂给GV生物合成途径的早期阻断突变体的交叉饲养实验表明，GE和任何defuco化合物都不是该途径的中间体。
Resequencing of the gilGT gene, which encodes a putative glycosyltransferase (GT) that is 495 amino acids (aa) long, from the Streptomyces griseoflavus Go3592 gilvocarcin V (GV) gene cluster, revealed that the previously reported gilGT indeed contains two genes. These are the large gilGT, which encodes the C-glycosyltransferase GilGT (379 aa), and the smaller gilV gene, which encodes an enzyme of unknown function (116 aa). The gene gilV is located immediately upstream of gilGT in the GV gene cluster. In-frame deletion of gilGT created a mutant that accumulated defucogilvocarcin E (defuco-GE). The results proves the function of GilGT as a C-glycosyltransferase. Deletion of gilOIII, which is located immediately downstream of gilGT, led to a mutant that accumulated gilvocarcin E (GE). This confirms that the corresponding P450 enzyme, GilOIII, is involved in the vinyl-group formation of GV. Cross-feeding experiments in which GE, defuco-GE, and defucogilvocarcin V (defuco-GV) were fed to an early blocked mutant of the GV biosynthetic pathway, showed that neither GE nor any of the defuco- compounds was an intermediate of the pathway.