Mathison L, Soliday C, Stepan T, Aldrich T, Rambosek J
Panlabs, Inc. Bothell, WA 98011.
Curr Genet. 1993 Jan;23(1):33-41. doi: 10.1007/BF00336747.
A long open reading frame (ORF) closely linked to the Cephalosporium acremonium gene cefEF was identified by DNA sequencing. The cefEF gene encodes the enzyme involved in cephalosporin C (CPC) biosynthesis known as expandase/hydroxylase. Complementation of a C. acremonium cefG mutant, as well as expression of the gene in Aspergillus niger, showed this ORF to be the cefG gene, encoding cephalosporin C acetyltransferase, which catalyzes the last step in CPC biosynthesis. Analysis of transformants containing additional copies of this gene showed that a direct relationship exists between cefG copy number, cefG message levels, and CPC titers. This gene encodes an enzyme for what may be a rate-limiting step in CPC production.
通过DNA测序鉴定出一个与顶头孢霉基因cefEF紧密相连的长开放阅读框（ORF）。cefEF基因编码参与头孢菌素C（CPC）生物合成的酶，即扩张酶/羟化酶。顶头孢霉cefG突变体的互补以及该基因在黑曲霉中的表达表明，这个ORF就是cefG基因，它编码头孢菌素C乙酰转移酶，催化CPC生物合成的最后一步。对含有该基因额外拷贝的转化体的分析表明，cefG拷贝数、cefG信使水平和CPC滴度之间存在直接关系。该基因编码一种酶，可能参与CPC生产中的限速步骤。
