Akkermansia muciniphila is a mucin-degrading bacterium commonly found in the human gut that promotes a beneficial effect on health, likely based on the regulation of mucus thickness and gut barrier integrity, but also on the modulation of the immune system. In this work, we focus in OgpA from A. muciniphila, an O-glycopeptidase that exclusively hydrolyzes the peptide bond N-terminal to serine or threonine residues substituted with an O-glycan. We determine the high-resolution X-ray crystal structures of the unliganded form of OgpA, the complex with the glycodrosocin O-glycopeptide substrate and its product, providing a comprehensive set of snapshots of the enzyme along the catalytic cycle. In combination with O-glycopeptide chemistry, enzyme kinetics, and computational methods we unveil the molecular mechanism of O-glycan recognition and specificity for OgpA. The data also contribute to understanding how A. muciniphila processes mucins in the gut, as well as analysis of post-translational O-glycosylation events in proteins.

Akkermansia muciniphila是一种常见于人类肠道中的粘蛋白降解细菌，它可能基于粘液厚度和肠道屏障完整性的调节以及免疫系统的调节，促进对健康的有益影响。在这项工作中，我们重点研究来自A. muciniphila的 OgpA，这是一种O-糖肽酶，专门水解N端肽键至被O-聚糖取代的丝氨酸或苏氨酸残基。我们确定了 OgpA 未配体形式的高分辨率 X 射线晶体结构、与甘草酸O -糖肽底物及其产物的复合物，提供了酶沿催化循环的一套全面的快照。结合O-糖肽化学、酶动力学和计算方法，我们揭示了O-聚糖识别和OgpA特异性的分子机制。这些数据还有助于了解A. muciniphila如何处理肠道中的粘蛋白，以及分析蛋白质中的翻译后O -糖基化事件。