STRUCTURE AND FOLDING OF A DESIGNED KNOTTED PROTEIN

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 子项目的主要研究者可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 极少数天然蛋白质具有多肽骨架打结的折叠构型。相对而言，人们对这些蛋白质的折叠能量景观或它们是如何进化的知之甚少。我们在这里通过设计一个独特的打结蛋白质结构来探索这些问题。生物物理 表征和X-射线晶体结构测定表明，设计的折叠到预期的配置，在该过程中将其自身打结，并且其可逆地折叠。该蛋白质折叠成其天然的打结构型比对照蛋白质慢约20倍， 被设计成具有类似的三级结构但不打结。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. A very small number of natural proteins have folded configurations in which the polypeptide backbone is knotted. Relatively little is known about the folding energy landscapes of such proteins, or how they have evolved. We explore those questions here by designing a unique knotted protein structure. Biophysical characterization and X-ray crystal structure determination show that the designed folds to the intended configuration, tying itself in a knot in the process, and that it folds reversibly. The protein folds to its native, knotted configuration approximately 20 times more slowly than a control protein, which designed to have a similar tertiary structure but to be unknotted.