Protein domains exist by themselves or in combination with other domains to form complex multidomain proteins. Defining domain boundaries in proteins is essential for understanding their evolution and function but is not trivial. More specifically, partitioning domains that interact by forming a single β‐sheet is known to be particularly troublesome for automatic structure‐based domain decomposition pipelines. Here, we study edge‐to‐edge β‐strand interactions between domains in a protein chain, to help define the boundaries for some more difficult cases where a single β‐sheet spanning over two domains gives an appearance of one. We give a number of examples where β‐strands belonging to a single β‐sheet do not belong to a single domain and highlight the difficulties of automatic domain parsers on these examples. This work can be used as a baseline for defining domain boundaries in homologous proteins or proteins with similar domain interactions in the future.

中文翻译：

---

β-链介导的蛋白质结构域相互作用。

蛋白质结构域单独存在或与其他结构域组合形成复杂的多结构域蛋白质。定义蛋白质的结构域边界对于理解其进化和功能至关重要，但并非微不足道。更具体地说，已知通过形成单个 β 折叠来划分相互作用的域对于基于自动结构的域分解管道来说特别麻烦。在这里，我们研究蛋白质链中结构域之间边对边 β 链相互作用，以帮助定义一些更困难的情况的边界，在这些情况下，跨越两个结构域的单个 β 折叠呈现出一个外观。我们给出了许多示例，其中属于单个 β-折叠的 β-链不属于单个域，并强调了自动域解析器在这些示例上的困难。这项工作可以作为未来定义同源蛋白质或具有相似域相互作用的蛋白质的域边界的基线。