CAJ | 학술논문

多烯大环类抗生素的生物合成酶属于典型的Ⅰ类聚酮合酶(PKS),这些生物大分子有着非常相似的化学结构和模块合成的形式.在本研究中,每个多烯聚酮合酶的单一结构域被作为系统进化分析的对象.我们发现,各类结构域在进化上出现了不同方向的倾向,其中,KS域在进化树中归成三大类,分别对应多烯结构的三大块区域;相对于KS域和ACP域表现出基因水平转移的倾向而言,AT和KR域则大部分都在单一的基因簇内部发生复制或者重组;而七烯类的FR-008和四烯类的匹马菌素的合成基因簇则极可能源自同一祖先,由此也佐证了多烯抗生素的共轭双键数目是由结构域的组织分布决定的.这些结果都为多烯大环组合生物工程提供了重要的启示.同时利用FR-008和匹马菌素的高度同源性,基于基因筛选的手段,我们分离到了一株新的产四烯大环类抗生素四霉素的链霉菌.
다희대배류항생소적생물합성매속우전형적Ⅰ류취동합매(PKS),저사생물대분자유착비상상사적화학결구화모괴합성적형식.재본연구중,매개다희취동합매적단일결구역피작위계통진화분석적대상.아문발현,각류결구역재진화상출현료불동방향적경향,기중,KS역재진화수중귀성삼대류,분별대응다희결구적삼대괴구역;상대우KS역화ACP역표현출기인수평전이적경향이언,AT화KR역칙대부분도재단일적기인족내부발생복제혹자중조;이칠희류적FR-008화사희류적필마균소적합성기인족칙겁가능원자동일조선,유차야좌증료다희항생소적공액쌍건수목시유결구역적조직분포결정적.저사결과도위다희대배조합생물공정제공료중요적계시.동시이용FR-008화필마균소적고도동원성,기우기인사선적수단,아문분리도료일주신적산사희대배류항생소사매소적련매균.
Biosynthases of polyene macrolides antibiotic belong to typical type Ⅰ modular polyketide synthases (PKS). Their common structural traits and similar module-biosynthesis suggested the closely evolutional relationship among their biosynthases. In our study,individual domains in each polyene PKS were selected to be taken phylogenetic analysis. We found that different kinds of domains exhibited different evolutional direction: three groups of KS domains responsible for three structural parts of polyenes; duplications or recombination of AT and KR domains mostly happened within one gene cluster while KS and ACP domain exhibiting more tendency to gene horizontal transfer; moreover, the number of conjugated double bonds is determined by PKS domains organization,since FR-008 (Fsc) and pimaricin (Pim) maybe came from one common ancestor. Based on the high similarity between Fsc and Pim, one gene-based screen method has successfully identified a new tetramycin-producing streptomyces strain.