羊毛硫肽SapB类多肽促进链霉菌形态分化作用的研究

SapB-like peptides promote morphological differentiation of Streptomyces

摘要:

【目的】链霉菌属于革兰氏阳性菌，以复杂的形态分化过程和强大的次级代谢产物合成能力为主要特征。链霉菌的形态分化与次级代谢产物的产生密切相关。Ⅲ型羊毛硫肽SapB能够促进天蓝色链霉菌气生菌丝体形成，暗示这类多肽可以作为靶标用于形态分化改造工程开发。本研究表征了SapB类多肽对多种链霉菌形态分化的影响，为该类多肽的工程化应用提供理论基础。【方法】生物信息学分析多个链霉菌基因组中SapB类多肽的生物合成基因簇，构建SapB类多肽的异源表达载体，利用接合转移方法导入不同链霉菌中进行异源表达，探究SapB类多肽对链霉菌形态分化的影响。【结果】SapB类多肽在不同程度上促进了多个链霉菌由营养菌丝向气生菌丝分化，表现为气生菌丝体数量的增多和分化速度的加快，缩短了链霉菌形态分化周期。【结论】SapB类多肽的过表达有助于缩短链霉菌形态分化周期，可用于针对链霉菌形态分化的工程改造。

Abstract:

[Objective] Streptomyces is a genus of Gram-positive aerobic bacteria characterized by complex morphological differentiation and potent secondary metabolite-producing ability. SapB, a class III lanthipeptide, promotes the morphological differentiation of Streptomyces coelicolor, which suggests that SapB-like peptides might be developed as targets for engineering of morphological differentiation. In this study, we characterized the effects of SapB-like peptides on the morphological differentiation of multiple Streptomyces species, aiming to provide a theoretical basis for the engineering of these peptides. [Methods] Bioinformatics tools were used to analyze the gene clusters for the synthesis of SapB-like peptides in the genomes of Streptomyces spp.. The plasmids for heterologous expression were constructed and introduced into Streptomyces spp. through conjugation. The colony and mycelial morphology were compared to reveal the effects of these peptides on the morphological differentiation of Streptomyces. [Results] SapB-like peptides promoted the differentiation of Streptomyces from vegetative to aerial mycelia. Specifically, they increased the aerial mycelia and accelerated the differentiation, thus shortening the morphological differentiation cycle. [Conclusion] SapB-like peptides can help shorten the morphological differentiation cycle of Streptomyces, demonstrating the potential for the morphological differentiation engineering of Streptomyces.