衔接重复序列对酵母菌絮凝蛋白功能的调控作用  

Regulation of tandem repeats on the function of flocculation protein in Saccharomyces cerevisiae

作　　者：李娥娥[1,2] 常琦[1,2] 郭雪娜[1] 何秀萍[1] 张博润[1] 

机构地区：[1]中国科学院微生物研究所,北京100101 [2]中国科学院研究生院,北京100049

出　　处：《微生物学报》2012年第1期69-76,共8页Acta Microbiologica Sinica

基　　金：国家自然科学基金(30970087)~~

摘　　要：【目的】了解絮凝基因FLO1中重复DNA序列B和D对絮凝蛋白Flo1p功能的影响,为构建遗传稳定的最小絮凝功能基因奠定理论基础。【方法】通过PCR和融合PCR方法分别克隆到完整的絮凝基因FLO1、重复DNA序列B和D分别缺失的衍生基因FLO1b和FLO1d,分析这些基因在非絮凝酵母中表达对细胞絮凝特性的影响。【结果】与完整絮凝基因相比,重复DNA序列B和D分别缺失后对酵母细胞絮凝强度没有明显影响,但不同基因在酵母菌中表达产生的絮凝特性受环境因素,如甘露糖浓度和pH等的影响有明显差异。FLO1中重复DNA序列B和D缺失后,细胞絮凝特性受甘露糖抑制的敏感性降低;同时对环境pH的改变具有更广泛的适应性。【结论】重复DNA序列B和D对絮凝蛋白Flo1p结构和功能具有调控作用,二者缺失后,特别是D缺失后会使絮凝蛋白在极端酸碱环境下更稳定。[ Objective] There are a large numbers of tandem repeats in FLO1, which are highly dynamic components in genome leading to the unstable flocculation profiles in Saceharomyces cerevisiae. The effects of repeated unite B or D deletion on the function of flocculation protein was studied to provide theory basis for constructing genetically stable flocculation gene with minimal size. [Methods] We cloned the intact flocculation gene FLO1 from S. cerevisiae YS59 by PCR, and constructed the derived genes FLOlb and FLOld with repeated unite B or D deletion respectively by fusion PCR. We analyzed the physiological characteristics of flocculation in yeast strains YSF1, YSFlb and YSFld containing FLOI, FLOlb and FLOld respectively. [ Results] YSFlb and YSFld displayed almost the same level of Flol-type flocculation as YSF1. However, flocculation of YSF1 b and YSF1 d, especially YSF1 d was more tolerant to pH change and mannose concentration than strain YSF1. [ Conclusion] Tandem repeats regulate the function of flocculation protein. Deletion of repeated unite B or D, especially D increases the stability of flocculation protein.

关 键 词：絮凝 絮凝基因 衔接重复序列 缺失 絮凝蛋白功能 

分 类 号：TQ926[轻工技术与工程—发酵工程]