Kotowska Magdalena, Ciekot Jarosław, Pawlik Krzysztof
Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland.
Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland and Department of Toxicology, Wroclaw Medical University, Wroclaw, Poland.
Acta Biochim Pol. 2014;61(1):141-7. Epub 2014 Mar 21.
Type II thioesterases were shown to maintain efficiency of modular type I polyketide synthases and nonribosomal peptide synthetases by removing acyl residues blocking extension modules. We found that thioesterase ScoT from Streptomyces coelicolor A3(2) is required for the production of the yellow-pigmented coelimycin by the modular polyketide synthase Cpk. No production of coelimycin was observed in cultures of scoT disruption mutant. Polyketide production was restored upon complementation with an intact copy of the scoT gene. An enzymatic assay showed that ScoT thioesterase can hydrolyse a 12-carbon acyl chain but the activity is too low to play a role in product release from the polyketide synthase. We conclude that ScoT is an editing enzyme necessary to maintain the activity of polyketide synthase Cpk. We provide a HPLC based method to measure the amount of coelimycin P2 in a culture medium.
II型硫酯酶通过去除阻碍延伸模块的酰基残基，来维持模块化I型聚酮合酶和非核糖体肽合成酶的效率。我们发现，天蓝色链霉菌A3(2)中的硫酯酶ScoT是模块化聚酮合酶Cpk产生黄色色素的天蓝色菌素所必需的。在scoT缺失突变体的培养物中未观察到天蓝色菌素的产生。用完整的scoT基因拷贝进行互补后，聚酮化合物的产生得以恢复。酶活性测定表明，ScoT硫酯酶可以水解一条12碳的酰基链，但活性太低，无法在从聚酮合酶中释放产物的过程中发挥作用。我们得出结论，ScoT是维持聚酮合酶Cpk活性所必需的编辑酶。我们提供了一种基于高效液相色谱法来测量培养基中天蓝色菌素P2含量的方法。
