Broadhurst R William, Nietlispach Daniel, Wheatcroft Michael P, Leadlay Peter F, Weissman Kira J
Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, CB2 1GA, Cambridge, United Kingdom.
Chem Biol. 2003 Aug;10(8):723-31. doi: 10.1016/s1074-5521(03)00156-x.
Polyketides from actinomycete bacteria provide the basis for many valuable medicines, so engineering genes for their biosynthesis to produce variant molecules holds promise for drug discovery. The modular polyketide synthases are particularly amenable to this approach, because each cycle of chain extension is catalyzed by a different module of enzymes, and the modules are arranged within giant multienzyme subunits in the order in which they act. Protein-protein interactions between terminal docking domains of successive multienzymes promote their correct positioning within the assembly line, but because the overall complex is not stable in vitro, the key interactions have not been identified. We present here the NMR solution structure of a 120 residue polypeptide representing a typical pair of such domains, fused at their respective C and N termini: it adopts a stable dimeric structure which reveals the detailed role of these (predominantly helical) domains in docking and dimerization by modular polyketide synthases.
来自放线菌的聚酮化合物为许多有价值的药物提供了基础，因此对其生物合成基因进行工程改造以产生变体分子有望用于药物发现。模块化聚酮合酶尤其适合这种方法，因为每个链延伸循环由不同的酶模块催化，并且这些模块按照它们作用的顺序排列在巨大的多酶亚基中。连续多酶的末端对接结构域之间的蛋白质 - 蛋白质相互作用促进它们在装配线中的正确定位，但由于整个复合物在体外不稳定，关键相互作用尚未确定。我们在此展示了一个120个残基多肽的NMR溶液结构，该多肽代表一对典型的此类结构域，在它们各自的C端和N端融合：它采用稳定的二聚体结构，揭示了这些（主要是螺旋状）结构域在模块化聚酮合酶的对接和二聚化中的详细作用。
