Tran Lucky, Tosin Manuela, Spencer Jonathan B, Leadlay Peter F, Weissman Kira J
Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK.
Chembiochem. 2008 Apr 14;9(6):905-15. doi: 10.1002/cbic.200700738.
Polyketide natural products such as erythromycin A and epothilone are assembled on multienzyme polyketide synthases (PKSs), which consist of modular sets of protein domains. Within these type I systems, the fidelity of biosynthesis depends on the programmed interaction among the multiple domains within each module, centered around the acyl carrier protein (ACP). A detailed understanding of interdomain communication will therefore be vital for attempts to reprogram these pathways by genetic engineering. We report here that the interaction between a representative ACP domain and its downstream thioesterase (TE) is mediated largely by covalent tethering through a short "linker" region, with only a minor energetic contribution from protein-protein molecular recognition. This finding helps explain in part the empirical observation that TE domains can function out of their normal context in engineered assembly lines, and supports the view that overall PKS architecture may dictate at least a subset of interdomain interactions.
聚酮类天然产物，如红霉素A和埃博霉素，是在多酶聚酮合酶（PKSs）上组装而成的，这些酶由模块化的蛋白质结构域组成。在这些I型系统中，生物合成的保真度取决于每个模块内多个结构域之间的程序化相互作用，其核心是酰基载体蛋白（ACP）。因此，对结构域间通讯的详细理解对于通过基因工程对这些途径进行重新编程的尝试至关重要。我们在此报告，一个代表性的ACP结构域与其下游硫酯酶（TE）之间的相互作用主要是通过一个短的“连接子”区域进行共价连接介导的，蛋白质-蛋白质分子识别仅提供少量的能量贡献。这一发现部分解释了一个经验性观察结果，即TE结构域在工程化装配线中可以在其正常环境之外发挥作用，并支持这样一种观点，即整体PKS结构可能至少决定了一部分结构域间的相互作用。
